Greenpois0n For Mac to jailbreak iOS 4.1 is now finally available from the chronic dev team.
Internally Greenpois0n uses the same exploit to jailbreak which is used by Limera1n jailbreak tool. Geohat’s bootrom exploit to jailbreak made them to drop the SHAtter exploit implementation.
We have already covered how to use greenpois0n to jailbreak iPod Touch 3G 4.1 iOS and iPod Touch 4G. Check it if you have any doubts on the jailbreaking process. Although the process is very intuitive once you start it.