iOS 5 Beta : Jailbroken courtesy Redsnow 0.9.8b1 for Mac
Did you update your iDevice to the iOS 5 BETA. Then this is possibly the best news for you. Redsn0w 0.9.8b1 has been released for Mac users, but given that it’s a tethered solution, you will have to plug in your phone everytime you need to boot up jailbroken.
This Jailbreak is meant only for developers who already have an activated iOS5 device. so make sure you know what you are doing before you take the plunge.