An interesting mobile phone network has just launched in the UK. Although owned by O2 and run by its execs, GiffGaff claims to be a completely separate "people-powered" operator, offering very cheap calls, texts and web browsing in exchange for customer involvement in the network.

You sign up, or get referred by an existing member, and then get sent a Pay-As-You-Go SIM card which will only work in unlocked handsets. You can then use that SIM card normally by topping up credit, or you can earn credit by doing certain things.

You earn £5 by introducing a new member. You earn £2 from a referral when people sign up, or 50p by telling friends about the service. There's other options too. Those points are doled out twice-yearly, in November and May.

Most impressively, there's a whole range of "tools" that consist of imagery and videos you can download. If you can turn one of those into an advert, and GiffGaff reckons it's good enough to use, you can become a "V.I.G." and get free texts, calls and web access for a year.

Speaking of web access, if you top up £10, then you get unlimited browsing for 6 months. Calls are free to other GiffGaff users, and 8p per minute to other networks. Texts are free to GiffGaff users and 4p to other networks. GiffGaff reckons that makes it the cheapest operator around.

What do you think? Does this add up? Or is it a noble but doomed attempt at a hybrid sharing and commercial business? Have you signed up? Tell us in the comments.