Edit #2: redsn0w replaces quickpwn and also handles jailbreak of iPhones without restore! (I believe the name quickpwn was retired because quickpwn.com is a stolen, fake site and the dev team does not want to support it).

Edit (June 20th): redsn0w 0.7 for 3.0 is out now! Get here

The dev team just released pwnage for OSX. So all your MAC users can now jailbreak your iphones. Note that this is pwnage not quickpwn. You can download it here. Also read the notes on the blog. Some highlights are:

* UltraSnow (3.0 unlock) is not available yet. If you have YellowSn0w, do not yet upgrade.

* If you have a 3gs, you must wait for an unspecified amount of time.

* iPod touch 2 users: Download here. If you have an iPod touch 2g, you must wait for a redsn0w update. Not ready yet.

* There is no windows version, there is no quickpwn yet. Coming later.

The basic pwnage guide should still work basically the same.