The iPhone 3GS is now supported in PwnageTool 3.1.3, assuming the phone was pwned at 3.0 or 3.0.1 - PwnageTool does not support the 3GS out of the box. If your iPhone 3GS has 3.1 preinstalled and is not Pwned then there is no tested jailbreak solution at the moment.
The iPod 2G is now supported in PwnageTool 3.1.3, assuming the iPod 2G was pwned at 3.0 or 3.0.1 - PwnageTool does not support the iPod 2G with 3.1 software out of the box.
1. GOLDEN RULE: If you are using a iPhone 3G or iPhone 3G(S) with ultrasn0w and rely on ultrasn0w to obtain cellular service then you should only update your device with an .ipsw that is made with the new PwnageTool. There are no second chances with this. You need to remember that PwnageTool will provide an upgrade path to newer versions of the iPhone software in the future.
2. Please read all parts of this post before downloading and using these tools.
3. Read items 1, 2 and 3 again and again.
4. At the bottom of this post are the bittorrent files for the 3.1 capable version of PwnageTool.
5. PwnageTool will work for the iPhone 3GS assuming you have already Pwned it at 3.0 or 3.0.1
6. PwnageTool will work for the iPod touch 2G assuming you have already Pwned it at 3.0 or 3.0.1
7. PwnageTool WILL work for Original iPhone (1st Generation), the iPhone 3G and iPhone 3G(S) and the iPod touch (1st Generation and 2nd Generation) but NOT the iPod touch 3rd generation.
8. For 3G and 3G(S) users who are Pwned, PwnageTool is your key to updating in the future, just remember to never install an update directly from Apple, always use an .ipsw that has been created with PwnageTool.
9. There is no Windows version of PwnageTool it is a Mac OS X tool only, we are not developing a Windows version of PwnageTool.
You can download PwnageTool 3.1.3 here. You can also try here if Pirate Bay is down.
You can find instructions on how to perform the update here.