My friend has an iPhone first generation, and when we plug it into the wall, the Apple shows up, but then it turns itself off, and the apple comes back up again, it is a vicious cycle. There is no way to get the phone to boot up the whole way.
Im having this same issue. It started last night. The time was showing the wrong time and date and all my contacts seemed to have been erased (which i didnt do), so i reset the phone (using the home button and top button) and it is now in the same "vicious cycle".
I have a meeting with the genius bar later today. Ill let you know what the genius' have to say, unless someone has a fix before then.