Every step you take: Hi-tech gadgets to catch a cheat

Lipstick on his collar was once the way to spot a cheat – but with the latest hi-tech gadgets, things have got really dirty. Rachel Shields puts spyware to the test

Worried that your lover might be cheating on you? Well, here's some good news, of sorts. Gone are the days when rummaging through your other half's pockets in search of incriminating restaurant receipts or phone numbers was the only way to confirm, or allay, your suspicions. And there's no need to hire a costly private eye, either.

For suspicions have given rise to a huge industry in spyware. No longer the preserve of professional detectives or secret agents, a world of surveillance gizmos is open to anyone who visits websites such as www.spyequipmentuk.co.uk and www.spymaster.co.uk. There the novice is confronted with minute cameras, homing devices and bugs. For £70 or so you can buy a widget that tells you what people are texting your partner. Now that's spying.

With minimal effort, it means anyone can acquire the ability to turn detective. Of course, there will be legal implications in using some of this kit, and it all depends on the context. There will also be moral questions for you to wrestle with. But if all's fair in love and war, then there's no longer any reason to wonder if your beloved is doing the dirty on you. Now you can find out for sure.

The Sim Recovery Pro £78.73

When you're equipped with the Sim Recovery Pro, sniffing a boyfriend's shirt collars for traces of another woman's perfume suddenly seems terribly passé. Primal, even. As any suspicious 21st-century lover will know, the mobile phone is the first port of call when snooping on one's other half.

Illicit text messages, late-night calls, unknown numbers – mobiles are a veritable treasure-trove of illuminating information. There is only one problem – if your partner is cheating, they'll also be guarding that phone like a hawk. So what's a wannabe sleuth to do? Simple – tap straight into their Sim card with the Sim Recovery system. Whip out their sim card, slot it into the Sim Recovery Pro USB stick, and then insert the stick into the USB port on your computer.

Bingo. Displayed on your computer screen will be the entire contents of your lover's phone. Their phone book, text messages, and even deleted text messages, will be right there for your perusal – you can even print it all out.

Mains Extension with GSM Audio £329

OK, so your lover wasn't using their mobile phone to betray you, but that doesn't mean they are in the clear. With most extramarital affairs starting in the workplace, the office is one front a jealous other-half cannot afford to ignore.

The Mains Extension with GSM Audio looks and works like a standard extension lead. The only difference is that this one allows you to listen in on every conversation taking place within a 15-metre radius of the device, with sounds transmitted to your mobile phone. Plug the extension lead into a mains outlet, wait 10 seconds, then use your mobile phone to text a code to activate the device.

You can then choose from a range of settings, including a "voice activation" option. This means that if the GSM picks up voice sound, it will automatically switch on and start recording, whilst alerting you via your mobile phone to this activity. You can then call the device and listen in. Unbeknown to your partner, if they are confiding in a colleague, they are also confiding in you...

The Key Shark £49

Pinging around the world all day, every day, are the billets-doux of the Noughties – emails. There is no juicier read than a love letter (especially if the author in question is your other half), but intercepting these modern missives is a little more difficult than riffling through their post box. Unless you're in possession of a Key Shark, that is.

This sounds sinister, and rightly so. Plug the Key Shark in between the keyboard and the computer and it will record every single keystroke that is typed, including passwords and special characters. Discreet enough to go unnoticed, you attach it to the keyboard when your other half isn't looking, unplugging it and reattaching it to your own computer whenever you fancy a good read. With this device, the inbox is no longer an impenetrable fortress, but an easily accessible window into your partner's private life.

Car Tracker £2,700

If you're paranoid that your partner might be up to no good, every moment that they are away from the workplace – and you – is time when they could be with someone else. You need to be able to find out exactly where they are, at any moment of the day. But how?

While donning a disguise and trailing your partner is always an option, what you really want is to be able to follow them from the comfort of your living room, and the Find It tracking system does just that.

Billed as "a versatile way to track high-value mobile assets" – code speak for stalking your lover – this little black box can be attached to almost any vehicle. The tracker uses GPS technology to keep tabs on exactly where the vehicle is – information which it then relays to your computer.

Load the mapping software on to your computer, send the unit a message asking for its position, and it will respond with latitude and longitude location points, the street level position also pin-pointed on a map. You can also use the unit to create a "virtual fence" around your partner, with the tracker alerting you only once the vehicle has travelled out of its "permitted" boundaries.

Super mini-ccd camera £130

You've ascertained that your lover has gone straight home after work, and is not out trawling the streets in search of your replacement. But what if they're up to no good at home? There is no point in monitoring their every move throughout the day, only to avert your gaze come night-time.

But home surveillance is tricky. While new electronic equipment may go unnoticed in an office, people tend to be pretty familiar with the contents of their own living room. Any obtrusive additions are likely to be detected straightaway, so this calls for seriously subtle spying. Which is where the Sony CCD pinhole camera comes in.

This camera is the smallest on the market, and can be squeezed into the tightest of spaces. Encased in black housing, it only needs a hole the size of a pin prick to see through, and blends in seamlessly alongside televisions, radio-alarm clocks, curtain rails and so on. And it can transmit high-resolution images even in low light. These are relayed – along with sounds in the immediate proximity of the camera – down a slim lead, to the main body of the camera. This has an AV connection that you can hook up to anything from a DVD or video player to an MP4 recorder, allowing you to sit back, and enjoy the show.

Landline Bug (UHF) £139

Spied on from every conceivable angle, your lover's landline now represents their last vestige of privacy. And you can strip them of that – although you may need to enlist the help of a technologically-minded friend for this one. The self-powered phone bug is supposedly easy to fit, but might prove tricky for technophobes.

If you do manage to attach this device to the speech wires in your lover's phone socket, you will be able to eavesdrop on all their conversations. The bug itself is powered by the telephone line to which you have attached it, so there is no need to change any fiddly batteries.

When a call is made or received from the phone line, the bud transmits this audio from the landline to a receiver, placed within a certain radius of the bug. Both sides of the conversations are transmitted, and the receiver can be connected to a voice-activated recorder – so you won't have to listen to hours of yawning silence in search of any incriminating chats.

Brilliant. But there is a catch. If you are caught operating one of these bugs, you may be in trouble – and not just with your partner. Although it is not illegal to buy, sell or supply these telephone bugs, you should have a licence if you intend to operate one in the UK.

All equipment from: www.spyequipmentuk.co.uk and www.spymaster.co.uk