QUOTE (Bairns Blue @ Jun 13 2010, 02:41 PM)

Can this only be done with a Jailbroken iPhone?
If so, what are the benefits of jailbraking when running 4?
Can you still use the App Store and update using iTunes when broken?
Thanks
Nope, can be done on any comparable iPhone by downloading iTunes 9.2 (mac only) and the correct version of iOS 4 Gold Candidate.
Got it on mine and I have never jailbroken it!