Geo-location specialist Quova is offering a service that lets wireless devices locate themselves by scanning for nearby Wi-Fi access points and GSM base-stations, and triangulating what they find against a master-list.

The software is based on a peer-to-peer wireless positioning app called Navizon, and is available for Windows, Symbian and BlackBerry devices. It relies on a directory of APs and base-stations compiled by volunteers - in return for feeding back their position data, the volunteers get free access to a 'virtual GPS' service offered by Navizon's developer.

Quova said that the methods it currently uses to locate fixed Internet users, such as mapping their IP address onto their ISP's network, often do not work on wireless devices. Marie Alexander, the company's CEO, said some wireless networks may cross national boundaries, for example, or roaming users might connect through their home point-of-presence.

Navizon can increase accuracy too, she claimed. She said that an IP address might only resolve to a 50-mile radius, whereas wireless triangulation can get it down to yards or metres.

The program requires the user's permission to run, and Alexander stressed that it is not about invading privacy. She said that it's about enabling access to services - typically services that you subscribe to, and which already know where you "ought to be".

She added that location data is increasingly important within e-business. For example, your on-line bank could check that you really are in the UK, and not a phisher calling from Russia, say, or the BBC could verify that you are entitled to use its UK-only IPTV service. Businesses could also use it to serve up geo-specific content such as where the closest branch is, she said.

Location data is increasingly important for fraud detection, she noted: "With cybercrime, the perpetrator tends to be in a different location to the victim, according to FBI and Interpol evidence. It's not like someone stealing your card, and 10 minutes later they're trying to use it down the road."