By Iain Mackenzie
Radio 1, Newsbeat
Online social networks already allow users to share photos, videos and update friends on everything they do. Now a new generation of sites is going a step further, using satellite positioning to track users' whereabouts.
Ian Walker has been testing the technology
Ian Walker is making his way across the car park outside of his office on Liverpool's Edge Lane.
His friends can watch his journey into work because he's connected to Bliin, one of the new generation of social networking sites that is using satellite positioning technology.
Users with Global Positioning System (GPS) enabled mobile phones log-on using a small application loaded onto the handset.
Their location can be viewed by other users with similar phones or through Bliin's website where the positions are superimposed onto Google Maps.
Just passing by
Ian, who is one of the first people to use the system in the UK, explained: "I had a situation where I was going to a restaurant and I wanted people to see when I would be returning.
"My friends followed me. I took a photo while I was outside the restaurant so they knew I was there. They saw me moving in the car - it even showed my speed."
Users will also be able to see when friends are nearby and contact them through the system.
The Bliin site shows your location pasted onto satellite images
As well as satellite tracking, the site includes other social networking features.
Bliin chief executive Stef Kolman told the BBC: "Not only will you be able to see what people are around you, but what they have left at certain locations.
"We call this a share. That can be photos, a video or pieces of audio."
Files are geo-tagged using the longitude and latitude taken from the GPS receiver.
Location-based social networking is expected to become increasingly popular as more phones integrate satellite technology.
Several other companies are developing sites, including Trackut and Canadian-based Kakiloc.
However the dominant websites MySpace and Facebook say they currently have no plans to integrate tracking systems.
That could change with the growing popularity of third party add-ons for social networks.
Kakiloc co-founder Martin Dufort said: "We're starting out, looking to see if we can do something for Facebook because it's got so many users.
"Social networking is a very volatile environment. People are going to one place and if they don't like the feature set, they are ready to jump to the next one.
"We need to capture their interest."
Not everyone is comfortable with the idea of location-based networking.
The UK's Child Exploitation and Online Protection Centre is looking at the possibility of the technology being abused.
On its website the organisation states: "This has significant implications in terms of grooming via mobile social networking sites with offenders potentially able to locate their victims in this way."
However, Stef Kolman from Bliin does not foresee the problem being any greater than with conventional social networking.
He said: "We offer our users visibility settings so you are not always visible to the public at large.
"You can choose to be visible only to your friends or even only for yourself so you can record your experiences."