As you know jailbreaking and unlocking tools for iPhone 2G and 3G were successfully released by the iPhone Dev-Team. Unfortunately all you lucky bastards with the new 3Gs will not be able to use them , because they are not compatible with the new device.
The good news , tho, is that Geohot is back at it again and it looks like he has already found a method to jailbreak the iPhone 3GS! Details of the exploit are still being gathered; however, it looks like GeoHot was able to insert a custom command to iBoot meaning sigchecks have been bypassed .
This should be a start for the iPhone 3GS (N88AP) jailbreak which has been dubbed purplera1n. Geohot has already activated purplera1n.com but is hosting nothing but an image as of now. The really good news is that if the jailbreak is successful the UltraSn0w unlock should be compatible with the iPhone 3GS as well.