Dont worry about it, the only difference between the sims is the amount of plastic! Watch this video to see how easy it is. I cut my tmobile & giffgaff sim down tonite and they work fine
http://www.youtube.com/watch?v=w2Pkm2PUG-c
Thanks to simon69c for recommending giffgaff to me. I received my sim within a couple of days and have now activated it. (& thanked simon69c as the referer). I have also cut the sim down by using the O2 microsim card as a template as seen in the video above.
For anybody buying a simfree iPhone I really recommend you consider giffgaff. They are now the only network offering unlimited data, from £10 a month.
The PAYG rates are brilliant too compared to the other networks
giffgaff runs on the O2 network, so if O2 coverage is good for you give them a try (and stick it to O2, who I am myself leaving in disgust)
If you do get a giffgaff sim, please use ayzee as your referral code, thanks