Android 2.3.1 gingerbread has been ported to work on the iPhone 3G, 2G and 1G iPod Touch. Ports for iPad, iPhone 3Gs and iPhone 4 to be release soon. Available only as a binary package anyone wanting to test have to follow the instructions HERE. Of course you will need a jailbroken iPhone or iPod Touch to get this to work. Check the video out. The developer also had this to say:
This is a preview release of Android Gingerbread (2.3.1) for Apple devices, I am busy with other projects for a few weeks and the other 3 active developers are working on porting openiboot to the iPhone 4, iPad and 3GS, so I thought I’d put a test build out for everyone to have a mess around with, please read this post fully before trying it.
This release is for iPhone 2G, iPhone 3G & iPod Touch 1G and is ONLY available as a binary package.