my iphone 4 I tried it and it says, "VERSION TOO NEW. YOU NEED TO DOWNGRADE TO 4.0.1/3.2.1 OR EARLIER, WHICH MAY BE IMPOSSIBLE" CAN YOU HELP MEemail@example.com
Looks like you upgraded your firmware beyond 4.0.1 There is a new redsn0w jailbreak out for 3G and Greenpois0n for 3GS and 4 iPhones. They are posted on the lastest few updates on this site.