Copied from www.thefuturelook.com:

3 into 2 won't go

3 SIMs blocked
3's aggressive price package featuring exceptionally low prices for voice calls (as well as the video-based services in which it's the UK's leader) has led to a sharp uptake in subscribers to the service. But some enterprising punters, apparently put off by the large size of many 3G phones, have been using their 3 SIM cards in 2G phones. Newsgroups have even sprung up on the internet advertising which handsets will and won't work with 3's SIM cards.

The practice has now been brought to an end by 3, which has made an adjustment to its technology which now prevents 3 SIMs from being used in non-3 handsets. A 3 representative said that the network isn't just about promoting cheap calls, it's about promoting a change in how people use their phones.

Is there anyway of getting round/cracking this so that 3 sims will work in 2.5 hansets?