Apple has disabled the IPCC tethering hack in 3.1 beta, no doubt they'll do the same in the real version. And looks like AT&T will follow suit with all their other smartphone plans and charge at least $55 for unlimited data and tethering. So even those who don't update to 3.1 might possibly get charged. Do you think that AT&T will go as far as to charge people tethering on their jailbroken iPhones? Can they tell the difference between 3.1 Tethering and 3.1 Jailbroken tethering? Tethering is something I might use very occasionally, so having an app like PDAnet or NetShare really wont' be all that bad even though the iPhone's built in Tethering is nice.