Winpwn 2.0 is out. Tutorial to follow. Get it here from theiphoneproject.org on a nice, fast server.
EDIT: I planned on making a guide for this but it just crashes on the iPwner step and iTunes fails to restore the device. I have tried two computers. Many folks are having a similar issue but many are not. At this time, I do not feel confident recommending using this and will not post the guide until it becomes easy.
EDIT: Here is a guide you can use.