Yep, a free iPhone unlock has been released by the the iPhone Dev Wiki. Well done guys!
Here are the download and mirrors links (copied from the wiki):
http://www.deadbeef.cn/files/iUnlock.zip
http://mirror1.deadbeef.cn/iUnlock.zip
http://www.tr0gd0r.com/iUnlock.zip
http://iphonedev.km20825.keymachine.de/iUnlock.zip
http://rapidshare.com/files/55044435/iUnlock.zip.html
http://www.megaupload.com/?d=FMI6OEE9
http://mirror1.deadbeef.cn/iUnlock_src.zip
http://iphonedev.km20825.keymachine.de/iUnlock_src.zip
http://gizmodo.com/assets/resources/2007/09/iunlock_src.zip
Update: Installation instructions are online on the Software Unlock page.