The Dev Team just released PwnageTool 3.1 for Mac OS X which will let iPhone 2G/3G and iPod Touch 1G users jailbreak their device. So far, only PwnageTool is available and is for Mac only, but the Dev Team is working on updating RedSn0w for both Mac and PC.
There is still now way to jailbreak the iPhone 3GS and the iPod Touch 2G and 3G but I assume these will come in the near future.
1. GOLDEN RULE: If you are using a 3G iPhone with ultrasn0w and rely on ultrasn0w to obtain cellular service, then you should only upgrade to 3.1 with a PwnageTool created .ipsw. – Stay away from Apple’s direct updates as described here and here please get up to speed on the whole subject by reading the information contained in these posts.
2. If you have an original iPhone (1st generation) then 3.1 unlock works with this PwnageTool release. iPhone 3G users upgrading to 3.1 will need to continue using ultrasn0w with a PwnageTool created 3.1 .ipsw
3. Please read all parts of this post before downloading and using these tools.
4. Read items 1, 2 and 3 again and again.
5. At the bottom of this post are the bittorrent files for the 3.1 capable version of PwnageTool.
6. This app is suitable for the recent 3.1 release.
7. This version of PwnageTool will NOT work for the iPhone 3GS.
8. PwnageTool WILL work for Original iPhone (1st Generation), Original iPod touch (1st Generation) and the iPhone 3G.