Bootlace 2.1 has just been released to install Android on your iPhone with no need for a computer.  It was just released by CPICH and Patrick Wildt (Bluerise).

Under the OpeniBoot tab you are able to install OpeniBoot, upgrade or remove it and configure an already installed OpeniBoot. Your device will be patched on first launch to allow the NOR to be flashed under iOS (This is a one off process – with patches thanks to CPICH & Bluerise).

Supported Devices/iOS versions (Not including GM seeds)
● iPhone 2G: 3.1.2, 3.1.3
● iPhone 3G: 3.1.2, 3.1.3, 4.0, 4.0.1, 4.0.2, 4.1
● Jailbreaks: PwnageTool, Redsn0w, Blackra1n

You can try Bootlace 2.1 by just downloading the following source  http://repo.neonkoala.co.uk repo to Cydia.