Sn0wbreeze 3.1.3 has been released which can jailbreak iPhone 2G, 3G and iPhone 3GS on the latest iPhone 3.1.3 firmware. One thing which is to be noted here is that it will work with iPhone 3GS only if it has the older bootrom (non-MC model). iPhone 3GS users who have upgraded to the stock 3.1.3 are still out of luck.

This is a guide geared towards iPhone users with Mac OS X. The steps are exactly same as they are on a Windows system. You can find the Windows version of the guide here.

The iPhone Dev-Team has just released redsn0w 0.9.4 to jailbreak and unlock iPhone 2G, iPhone 3G (No unlock for 3G), iPod touch 1G and iPod touch 2G (older Non-MC models only). Do not update to iPhone 3.1.3 firmware yet if you want to preserve your unlock for iPhone 3GS, iPhone 3G, iPod touch 2G (new models) and iPod touch 3G. This is because the new iPhone 3.1.3 firmware updates baseband to 05.12.01 on iPhone 3GS and iPhone 3G which makes it impossible to jailbreak and unlock iPhone 3GS and 3G.