ZiPhone: jailbreak any version iPhone out of the box, including 1.1.3

via engadget

We're not yet entirely sure how it works, but iPhone hacker Zibri's just released a new app he's calling ZiPhone, which claims to jailbreak any version iPhone -- including new 1.1.3 phones right out of the box -- without messy downgrades and baseband changes. We haven't tested it ourselves, but prepare for the onslaught of downloaders to take it offline in five... four... three...

http://zibree.blogspot.com/2008/02/ziphone.html