The iPhone devteam found a way to jailbreak your iOS 4 device by going to jailbreakme.com with Safari on your iPhone. The release came out late last night, and the servers have been swamped since. Once you go to the site you will be presented with a slide to jailbreak screen and voila. If successful a message will show up that Cydia has been added to your home screen.
For those questioning, technically this is legal now that the US Government has legalized jailbreaking!
Jailbreak Me main screen image
