iPhoDroid is a program designed to install Android on an iPhone 2G or 3G. It is very interesting because it helps to have all the benefits and functionality of the Android system, while maintaining the iOs operating system (multi-boot) on your phone. It is easy to implement, even if other functions are still missing (unable to make calls). To find out, just download it as it is an open source program.
iPhoDroid_1SHOT_R13j_3G_Mac-0.6 Beta.zip, iPhoDroid_1SHOT_R13j_3G_Mac.zip