OK, truth be told, we hacked our 1.1.3 iPhone a few weeks ago - but it was a pain in the a$$. Took a few hours and we had to upgrade, downgrade, sidegrade etc. A lot of people who aren't as stupid/bored/daring have taken a pass on the 1.1.3 jailbreak until something easier came along. That something might be:
Zibri's ZiPhone
It is a one step jailbreakerwe are trying it now - more to come shortly
Update - it went pretty smoothy. Remember to quit iTunes helper application, do the reset while you are putting it into the cradle and that it takes a little while. Have fun!