This 20 MB zip file is released by the iPhone Dev Blog very recently. As per this "unofficial" official blog of the "iphone-dev team" this tool unlocks and jailbreaks older iPhones with 2.0 firmwares, it also jailbreaks iPhone 3G and iPod Touch with 2.0 firmwares.
Here are some download options:
More download options here.
In case you use this application, share us your comments for fellow bloggers and iPhone users