Limera1n has been released for all the iOS devices out there that include iPhone 4, iPhone 3GS, iPad, iPod Touch 4G, and iPod Touch 3G.
Note that it is available only for the Windows platform. However, its developer has promised that Mac and Linux versions are the pipeline. Let us know if it works for you all! [Download]
Also see:ipad 4.1 jailbreak, iphone 4.1 jailbreak, iphone jailbreak, ipod touch 3g 4.1 jailbreak, ipod touch 3g mc 4.1 jailbreak, ipod touch 4.1 jailbreak