Notorious Planetbeing – member of the famous iPhone Dev Team – just released a vid showing he managed to install Google’s Android operating system on an iPhone 2G.
In the video below Android is demonstrated on an iPhone 2G; however, it should be pretty simple to port forward to the iPhone 3G. The 3GS will take more work.
Planetbeing thanks CPICH for reversing support, harmn1, posixnina, jean, marcan and saurik for patches, and last but not least, TheSeven for his work on the FTL.
Pre-built images and sources can be found at http://www.mediafire.com/?xqjzn12igfn.