If you ever been used PSGroove or PSJailbreak, then PSFreedom has similiar functionality. And the developer named the project on porting PSFreedom on iPod touch and iPhone, IPhoneLinux. And it's been tested and working almost flawlessly, therefore they released the source code. Unfortunately, the project failed to make the Backup Manager to work, but don't worry they are working on it for the future release.
As I mentioned above that the port of PSFreedom only applies for iPhone 2G, 3G and 1st generation of iPod touch, also your iDevice have already have OpeniBoot installed to make the iDroid able to run.