I posted this in the UK iPhone thread, but just incase anyone from the UK doesn't use that thread, I thought I'd post a main thread regarding this. Tonight I was prompted to update my carrier settings while simply sitting browsing the web on my iPhone, I wasn't connected to iTunes. From what I can see, it's added the option for Internet Tethering. I tried it on my SIM free iPhone 4 running on O2 Unlimited with two months of my free data and WiFi bolt on remaining (carried over from my 3G bought in Sept 2009). I don't remember this setting being there prior to the update to my carrier, which is now O2 7.3, and I've taken some screens and posted them below. For the record, while only getting GPRS at home, I still managed to connect to the internet on my iMac with tethering switched on in the iPhone settings and choosing iPhone from the list of connections in the Network preferences panel. If this setting was there from the get go, then ignore this thread. However, I'm sure I would have noticed this in my carrier settings and it jumped out at me after my phone reset once accepting the carrier update and going to see if anything had changed. My iPhone 4 was prompted for the update around 8:30pm (UK time).