I saw this this morning and thought it was one of the coolest things I have seen a while. One of the gang from the Dev Team that goes by the name of Planetbeing (with the help of a few others including Posixninja, Saurik, TheSeven, CPICH and maore) has found a way to push Android onto the iPhone.
Unfortunately it does not work for the 3G and 3G S just yet but they have it working on the original hardware. This is VERY good news for owners of the Original iPhone as Apple is cutting support for them with OS 4.0. It could also mean that people will finally see Flash running on iPhone hardware
Planetbeing says that the port to the 3G should be fairly easy but that the 3G S will take a little more time.