For all those out there who need tethering. but cannot wait for there providers to roll out support, there is a very easy way for you to enable tethering on most networks across the world for free.
First head over to help.BenM.at in Safari on your iPhone.
Select Your Country
Select Install Now
Now go to Settings > General > Network > Internet Tethering > On, and now you have tethering.
Update: Some are reporting that this procedure could disable MMS and visual voicemail depending on your country and carrier.
Update 2: Techradar reports that O2 UK has responded to the tethering hack saying, “we reserve the right to charge customers making modem use of their iPhone or disconnect them.” This assumes O2 can identify such customers.