According to Appmodo (via Daring Fireball), AT&T will start supporting MMS on the iPhone in July, so the wait won't be much longer. The site claims a source inside AT&T states the tethering option will also be available at the end of July, priced at $55 per month. The blog isn't very clear about the math, but we'd assume the existing plan is included in the pricing. With last night's news that it's relatively easy to enable this feature, it would seem to make sense that AT&T would want to get this feature supported and fast, so they can start charging customers. How much additional would you pay for tethering?