Guys behind Bootlace are working hard to port Android on iPad and iPhone 4 via OpeniBoot. Bootlace currently installs Android on iPhone 3G and 2G only. The video and screenshots below show that iPad and iPhone 4 support will be added soon.
For those who don’t know, OpeniBoot is an open source implementation of iBoot for Apple iPhone, iPad and iPod Touch devices. It allows booting of unsigned code such as linux kernels on the device. OpeniBoot is critical for the booting and usage of linux on the iPhone as it sets up and initializes many devices ready for the linux kernel to take over. Many iBoot functions are replicated here, however when booting iOS iBoot is chainloaded from the NOR to guarantee iOS will boot without problems even with OpeniBoot installed. Open iBoot currently supports iPhone 3G, iPhone 2G and iPod Touch 1G.
Open iBoot on iPad [Video demo]