Geohot has released it’s long awaited 4.1 jailbreak. Its called limera1n, and i tested it this morning worked perfectly. Some people report that it removes 3g features from ipad 4.2 but it’s safe for most people. Also its really easy to use it’s not tethered, just click one button and DFU.
Here is the download link. But remember it dosent work very good with iphone 3gs!!