Hello, for those of you with an Iphone (or iFern as they say over here in E.Yorkshire) I found a pair of websites that open up the tethering option on the phone. Its not in the O2 T&C's so they could charge you loads if they found out I suspect, but my reconing is that they probably wont charge you unless you really take the piss!
THis is the site I found out about it from:
http://www.engadget.com/2009/06/18/how-to-tether-your-iphone-running-os-3-0-without-jailbreaking/Its about as simple as pointing safari on your iphone to this URL...
help.benm.atThe website says it may leave visual voicemail and MMS a bit funny, but seems to be OK on mine OS3.01,
Hope this helps someone - no need for O2 3g dongle if out of the house now! In fact this post is done using the tethering
TT