The iPhone Dev-Team's Redsn0w has been updated for Mac-tethering-only iPhone 4, 3GS, iPad and iPod Touch jailbreaking. RedmondPie's tried it out and found it works fine, but does warn not to use Redsn0w if you're using a carrier unlock. [RedmondPie]
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Ok can't seem to find the answer to this. But does the jail break allow you to skip Apples required activation for iOS5? Or do you still need a developer account to use iOS5 at all?