ALL modells:                           http://blackra1n.com/
                                                 http://jailbreakme.com/ (WARNING:tipe this in your iPhone/iPod Touch Browser)
                                                 http://spiritjb.com/

Jailbreak ios 4.0:                      http://jailbreakme.com/  (WARNING:tipe this in your iPhone/iPod Touch Browser)
                                                 http://ih8sn0w.com/index.php/products/view/sn0wbreeze.snow

Jailbreak ios 4.1:                      http://www.greenpois0n.com/          

                                                 http://limera1n.com/  

All of those Jailbreaksolutions are untethered. That means, that they are there after a retart,too.