Dual Boot Android OS and iOS on iPhone 3G and iPhone 2G
If you have a jailbroken iPhone 3G or iPhone 2G, you can dual boot between Android OS 2.2.1 Froyo and iOS 3.1 to iOS 4.1. The installation really isn’t that difficult, especially if you already have a jailbroken iPhone (apparently it must be jailbroken with PwnageTool, redsn0w, or blackra1n, not quite sure why), it’s basically just a matter of downloading a few apps (Bootlace and OpeniBoot), and then installing Android onto the iPhone.
The following video walks you through the installation process, it’s pretty short and easy to follow, courtesy of RedmondPie:
Apparently Android runs reasonably well on the iPhone 3G, but some features don’t work, making this more of a cool hack than a practical installation at this point. If you don’t have an iPhone 3G or you just don’t want to deal with this hack, you can also run Android OS within a virtual machine on your Mac or PC, it’s a free download too and completely pain free.