For those that dont know or havent been up to date on this, the jailbreak for iOS4.1 is out from limera1n and greenpoison. Both will jailbreak 4.1. Just follow the steps on screen, takes a couple of mins. Have fun. http://limera1n.com/ http://www.greenpois0n.com/
Just be sure to change your file system password IMMEDIATELY after jailbreaking or you're leaving yourself wide open.