Max Clifford, publicist
The biggest part of PR is protection, and if you're aware and react quickly you can stop emerging problems becoming problems. If you can't, it can take months to try and repair the damage. For instance, I might get a call from a paper at 5pm to say they're about to run a story, and I have an hour to prove it's not true. I travel a lot, and if I didn't have that mobile phone, the story would emerge without me knowing, and it would be damaging to my client. That happens more and more now. Speed is important and communication is vital in my world.
Saying that, I'm probably the most untechnical person in the world: I don't even send e-mails. I resisted using a mobile phone for a long time because I realised that I could never be "away" if I had one. But when I got a mobile about seven years ago it became as important as I thought it would. Things would be so much more difficult without it now.
Two of my phones have special ringtones - one with "Love Me Do" by the Beatles, because I started out with the Beatles in '62, and it was the first record I worked on. The other one has "I'm Forever Blowing Bubbles" - because Claudine, my PA, is a West Ham supporter. We keep all the contacts in the office, with back up phones for me so there's a replacement straight away if one is lost: it's become too important now. Major disasters have been avoided on many occasions because of having a mobile phone. For me, it's been wonderful.
Lauren Laverne, music presenter
I was a bit late getting an iPod, but I got a 40-gig one last Christmas, and use it for everything. I must get sent about a hundred CDs a week, so I always have a backlog: I sit down to listen to them on the computer and anything I like the sound of, I 'Pod' it. Pod is the new verb now, you know. I make about two playlists a month of stuff I get sent that I really like.
When I started off using it, I thought of it as carrying around your whole record collection in your pocket, but now that's not the way I see it: it's like having the ultimate compilation. I've got so much on there that I'll have to get a 60-gig one soon. But it's so handy, especially for my CD:UK work, when I need to download tracks on to it that I have to know. We've had all sorts of characters in who I've investigated.
On a practical note, I've got special earphones for my iPod which I love. I've got a bit of a problem in that I've got really tiny ears and they're very small inside. When I got fitted for my earpiece for television, the man freaked out, they were so small. Ever since then I've worried that they'll heal up and I won't be able to hear any more. So especially for small ears, I have amazing noise-reduction earphones from Sony. They've got a silicon edge that moulds to your ear and creates a barrier. Excellent if you've got particularly small lady ears, and they're white too, so they still look like the normal iPod ones.
Lauren Laverne presents 'CD:UK', on Saturdays at 11:30am on ITV1, and the Xfm Breakfast Show, from 6am on weekday mornings.
Patrick Moore, astronomer
I would have to choose my telescope, of course. One has to have a telescope in my line of work. The one I'm nominating isn't new, I have had it for years - I think I bought it around 1961, and have been using it ever since. I can't remember how much it cost, but in those days it certainly wasn't wildly expensive. My telescope has a 15-inch refractor that I use to make all of my astronomical observations. It's much better than other normal telescopes, because it's more powerful. It also has a high magnification that enables me to observe the moon and planets. I've been doing this for 40 years now, and it suits what I do very well.
Other people still use it too - we had a Mars party here about a month ago where friends turned out to have a look at the sky, and a photograph taken with that telescope with modern equipment was much better than anything else. The thing is that a telescope won't deteriorate: the world's biggest refractor was built in 1895 and it's still working. I suppose if it does deteriorate you could always play football with it, but that's unlikely. I have to have my telescope serviced only periodically.
You should never look anywhere near the sun with a telescope: you need to learn your way about the sky. The best thing I've seen through my telescope is the moon. It is a most memorable sight. Perhaps if money were really no object I'd buy a really big refractor but then I wouldn't have to do a thing and my career would be over.
Jason Gardener, Olympic athlete
My life revolves around time, around fractions of seconds. The time it takes to blink an eye is probably a tenth of a second - but first and last place in a race could depend on that blink of an eye. Hundredths of seconds are what can make what I do a success or failure. Therefore the Starting System I use to train with is invaluable.
It involves quite a lot of equipment and wires. The starting block is wired to the system, so that it gives a digital signal when you disengage from it. The system then gauges the time it takes for you to pass through the beam at the finish line. That beam is what sends a signal to the stopwatch, so you get a really accurate time. It means I can see exactly what my times are at certain times of the year, and how my style of training is working. There are so many variables: it all depends on the time of year, what training I've put in, whether I'm ill or not. This system means I get regular feedback. I'm used to knowing how my body works, and what it needs for performance, so if certain training is not recording a good time, that's a real worry.
I'm fortunate to have had the system for the past couple of years. It's very expensive - around £10,000 - but it's worth every penny. Otherwise you're just guessing, and you can't afford to guess. In the past I had to rely on subjective assessment of how the training was going, or the coach's finger on the stopwatch. That's just not as reliable as it should be when you're dealing with one hundredth of a second. In competition, there's no hiding place.
Mark Eley and Wakako Kishimoto, fashion designers
We've had this laptop for about eight years now, and improved it as we got some money. So it started as a humble PowerBook and now it's a G4. It's got a ridiculous amount of information on it: around 8,000 e-mails as well as all correspondence, communication and planning. We back it all up, but are rubbish at deleting. We're not very good at the technical specs - someone called Matt helps with that. He's a Mac doctor - he says we need more memory and we go out and get some.
We went down the Mac rather than the PC route just because of natural instinct. Now as well as our communications and finances, we use it for photographic materials, writing DVDs, CDs, designing portfolios, press materials, consultancy information, and so on. Everything is part of a larger portfolio of information, and this machine gives us the visuals and sound. It's important for research, too, and having internet access is a major plus. Work used to be done on a typewriter, and photos on film and transparencies.
This laptop is like an off-roader, completely wrecked and dented, not one of those sleek posh ones. It's taken everywhere in a bag - open it and crisps fall out. A lot of our work is done by hand, and the computer is a tool to document that. It's not a tool to create, it's a tool to assist the creation. Eley Kishimoto Store, 40 Snowsfield, London SE1, enquiries 020-7357 0037.
Jimmy Carr, comedian
My Blackberry is technology that has caught up with science fiction. It sends me all my e-mails and lets me go on the internet while I travel up and down the country doing gigs, or am in studios; I can't imagine a better world. It used to be that when I was out and about I generally wasn't able to get messages about penis enlargement or Viagra, whereas up-to-the-minute information is sent to me all the time now. Having e-mails and being able to deal with them little by little during the day means I've nothing to do when I get in - I've already done it in the queue in Starbucks. I love that. I like being constantly bombarded, it makes me feel somehow important.
I got this gadget only about three months ago, and it is such a boon to be able to do bits of admin on the road and be contactable all the time. Also, it's a nice size. About two years ago I realised phones were getting too small. This has a nice big colour screen which lets me go through all my texts and e-mails, as well as a memo pad that I write jokes on. I use the memo pad about 10 times a day: the thing about being a comic is that you don't sit down to write jokes - things just come to you in the middle of a conversation and you make a note of it. I used to rely on a hundred different scraps of paper, and frankly that was suboptimal. Now I e-mail myself.
Details of Jimmy Carr's nationwide Off The Telly tour are available on www.jimmycarr.com and his new DVD, 'Stand Up', is out on 7 November
Sarah Waters, writer
I'm not a fan of Rupert Murdoch, and I think supporting his media empire is pretty indefensible. But I'd be a hypocrite if I didn't confess that I absolutely love my Sky+ box. Anything that allows me to watch wall-to-wall Simpsons, Futurama and Turner Classic Movies can't be all bad.
Without wanting to sound like an advert, Sky+ is very easy to work. I usually come late to new gadgets, but then instantly can't live without them. My girlfriend's a bit of a gadget queen - she usually tries things out, then passes them on.
I often watch television at the end of a writing day; it seems to me to involve a combination of physical torpor and low-key mental stimulation that's absolutely perfect when you're a bit knackered. Sky+ makes watching television even less stressful, because you know what you're going to get - you don't have to watch anything just for the sake of it, but have, say, 20 episodes of Seinfeld stored up, or six old films. It's also incredibly easy to use; and you can fast forward through the adverts. It makes TV watching a much more private experience. I don't know if that's good or bad. But I like it. It's the reward at the end of my day.
It's so easy to record and store programmes. It's like a TV iPod. The only drawback, in fact, is that it doesn't store enough.
Sarah Waters is the author of 'Tipping the Velvet' and 'Fingersmith'. Her new novel, 'The Night Watch', is published in February (Virago).
Pen Hadow, explorer
I cannot do without my custom-made all-in-one immersion suit. In Spring 2003 I used it to become the only person to successfully reach the north geographic pole from Canada without re-supply. In the popular press I was referred to as the "human icebreaker": I pulled the suit on over my polar boots and clothing, lowered myself through thin ice and swam, towing my sledge. The images of me swimming in that suit became a visual symbol of the urgency of the global warming debate. It illustrated the difference between the Antarctic and the Arctic Ocean ice cap - the former is up to 4 km thick; the latter has an average thickness of just 9 feet.
The suit is made of something called Hypalon, which is waterproof, extremely durable, abrasion resistant, lightweight and strong. It has to be very strong because otherwise you'll shred your hands breaking ice. I called it Mr Orange and he and I didn't get on. This was firstly because doing anything brave - such as lowering myself into the inky black waters of the Arctic Ocean up to 900 miles away from the nearest human being - always struck me as being an unnatural act. Secondly, I felt vulnerable from attacks from polar bears.
One of the problems with Mr Orange was that it was hugely buoyant, with lots of trapped air, which is a wonderful insulator. But if I'd dropped into the ice head-first the air would have risen to my boots and I wouldn't have been able to get up. It would have been a most undignified way to shuffle off this mortal coil.