With RedSn0w 0.7.2 iPod Touch 1g and 2g users can jailbreak 3.0 firmware on Windows. Before following this guide please restore your iPod Touch to 3.0 firmware. To get the 3.0 firmware you have to connect to iTunes, check for updates, and buy it for about $10. Yes Apple is screwing you. Positive side is that if you have both a 1g and a 2g you get to download firmware for both for $10.
You will need RedSn0w 0.7.2 which you can download right here
along with the 3.0 firmware file for your device. Since you already bought and downloaded the firmware in order to upgrade to 3.0 you can find it one your computer
iPod2,1_3.0_7A341_Restore.ipsw is the iPod Touch 2g 3.0 firmware file.