I have no idea why this has taken so long or why I did not think of it. There is a new project on kickstarter called juicetank that is an iphone4, 4s case that has the AC plug built it!  Yes, make perfect sense when you think about.  New to recharge your phone?  No adapter, no chord, nothing.  Just plug your phone into an AC outlet and there you go! Check out the Video at the end of the post.

The case is not much bigger then other iphone battery cases I have seen, and since its kickstarter there is no way I can get my hands on it to try it myself, but it looks pretty nicely designed and should feel comfortable in your hand while in use. Now the only question I have is how hot will this get?  Hopefully not much since your phone is sitting in the case and we all know iphones and heat do not mix well.  Odds are it does not recharge at a super fast pace to avoid this problem.

Its a kickstarter project so if you get in early you can get a discount.  Here are the stats for the first two entry points.