Bootlance is a free application that can be found in Cydia via the BigBoss repo. It enables you to install Android OS on your iPhone without the need of a computer. Yesterday it received an update to support the first Gen iPod Touch.
Bootlance is compatible with iPhone 2G: on iOS 3.1.2 and 3.1.3, iPhone 3G: on iOS 3.1.2, 3.1.3, 4.0, 4.0.1, 4.0.2 and 4.1 and also with the first gen iPod Touch since the last update. Ones again, you can get Bootlance for free in Cydia via the BigBoss repo.