Just a quick heads-up: redsn0w has been updated to 0.9.8b5, adding support for Apple’s new iOS5 beta5 . Please use this only if you’re a jailbreak app developer with a legit Apple dev account, and remember it’s a tethered jailbreak for now!
Download RedSn0w 0.9.8b5: Mac, Windows
If you don’t know how to use redsn0w, check out our previous tutorial (point it directly at the beta5 IPSW)