You now don't have to do any downgrading or *******ing. Seems you can just run a little command in terminal (Make sure you are on OS 3.0 on a 3G iPhone and iTunes 8.2): "defaults write com.apple.iTunes carrier-testing -bool TRUE" After that, the steps become a lot more simple. 1. Download this file (for AT&T) and mount the disk image (thanks Gizmodo) for other carriers, try here. 2. Option-click on "restore" in your iTunes with your iPhone attached. Browse to the opened disk image file and hit OK. It will update phone settings for a few seconds. 3. You have tethering. Now go into your iPhone/settings/general/network/Internet Tethering and turn it on. Boom - 3 steps to tethering... Oh, and how to you like cut and paste and spotlight search?