After GeoHot’s release of limera1n the Chronic Dev Team have made a rapid turnaround to engineer GeoHot’s exploit into their greenpois0n tool rather than burn the original exploit they used in greenpois0n. You can download the release from the greenpois0n website for both Mac and Windows. No beta, no RC1. Just a fully tested and well engineered jailbreak tool for iPod touch 3G/4G, iPhone 3GS/4 and iPad for devices on iOS 4.0.1 and up.
Don’t forget to consider donating for their hard work (and stress) in getting this tool out to the community.