Time was when a mobile was just for talking.
Then came text messaging, radio, limited internet access, video calling and music downloads - and now comes broadband.
On Friday, the mobile network 3 launched its X-series phone service with high-speed internet access.
Although the near 1Mb speed isn't yet comparable with that enjoyed by many broadband users on their home PCs, the new service has some impressive selling points. For a flat monthly fee, consumers will be able to make unlimited calls over the internet, watch television, access their own home PC remotely, and access internet and messaging services from Yahoo!, Windows Live Messenger and Google.
Essentially, two price tiers are being offered, Silver and Gold, at £5 and £10 a month respectively. This charge is made on top of your existing monthly tariff.
Both packages offer unlimited internet access while you're on the move, and free national and international calls to users of Skype, the low-cost internet phone service.
"Potentially, this [last point] is the most compelling benefit in this package, and means 3 customers can make free calls to other Skype users anywhere in the world from their mobile," says Robert Kenley of price comparison website moneysupermarket.com.
The launch of 3's X-series comes as the number of mobile phone users accessing the internet on their handsets has risen steeply.
Thirteen million UK customers were recorded as having used their phones for downloads and browsing the internet in July, according to the Mobile Data Association. In September, the figure was 14 million.
Mobile internet, or "WAP" (wireless application protocol), has been around since 2000 but initially users complained of clunky service, allowing access only to limited content, such as providers' own specially modified pages.
Technological advances and improved microchip processing power have, in the past three years, allowed mobiles to become more sophisticated, so that users can now browse ordinary internet pages, albeit rather slowly. Today, most mobiles offer internet access, and 3's new service is being touted as likely to spark a fresh round of price cuts. This, the industry hopes, will convince consumers to carry on making heavy use of their mobiles.
But internet services on offer vary wildly - so will you be getting value for money as a customer?
The answer depends on which provider you have and whether you are on a contract or pay-as-you-go.
Most providers still take a "walled garden" approach, letting you browse only their own mobile internet content, such as Vodafone live! or Planet from 3. At least this is usually free, or very cheap. It allows the network to direct the phone user more easily to sites where they can buy music tracks and ringtones from the same operator.
Beware: the cost of such purchases can be far higher on a mobile than on a home PC. Depending on your mobile provider, music can cost between 99p and £1.50 per track. In comparison, download services such as iTunes and Napster usually charge 79p per track.
Here's a guide to what you can expect from different providers.
Its "web 'n' walk" service allows easy access, via a Google search engine, to the entire internet from a mobile, just as if the user were on their PC.
Unlimited web browsing is available to contract customers for £7.50 a month on top of their regular contracts, and to pre-pay customers for up to £1 a day.
"You need a suitable phone such as an XDA from O2," warns Chris Frost of the price comparison service uSwitch.com.
The X-series offer outlined above is for pay-monthly customers only; like 3, it also lets you visit any internet sites.
Mr Kenley adds that, since 3 is already offering a large number of mobile phone tariffs with free minutes, there's a danger that those who sign up for free Skype calls won't be getting the most from the deal unless they ensure they have first used all their free minutes under their normal tariff.
Web access is charged by the amount of data used.
Watch out if you want to download music, ringtones or video clips to your phone - O2 is the most expensive provider for downloads, according to research from uSwitch. Ringtones cost £2.50, compared with just 99p on some rival networks. Music tracks start from £1 and video clips from £1.50.
Vodafone live! is free to both contract and pay-as-you-talk customers.
Wider mobile internet access on sites specifically adapted for mobile phone viewing, such as BBC News, costs £2.35 per megabyte (MB) of information downloaded for contract users. Pay-as-you-go customers are charged £7.50 per MB.
Access is via its own Orange World site.
Monthly contract customers can choose pay-as-you-use from £3 per MB downloaded, or sign up for a bundle at cheaper rates.
Pay-as-you-go customers pay a fixed £4 per 1MB.Reuse content