Wow. This would be awesome although my battery probably would die a lot.

Something significant has obviously delayed the original September launch of push notifications, Apple's solution to not allowing apps to run in the background. MacRumors hears that Apple is considering allowing real background processes instead.

...

MacRumors says that if what they're hearing is true, and Apple allows apps to run in the background, it would happen with the iPhone 3.0 software. On the current iPhones, it would likely be restricted to one or two processes at a time, but with the beefier hardware of the next-gen iPhone, it'd be less restricted.

....

 http://i.gizmodo.com/5145303/rumor-iphone-30-might-let-apps-run-in-the-background-for-real-multitasking