Güncelleme #14: We’ve released version 0.9.9b6 of redsn0w, with both a functional fix and cosmetic fix for iOS5 jailbreakers. For iPhone3GS owners with the 06.15 baseband, this redsn0w eliminates the network crash you saw when using Location Services in iOS5 (in fact, you don’t even need to disable Location Services anymore during the initial setup). The cosmetic fix is to the visual countdown you see when going into DFU mode.
It’s okay to re-run this redsn0w over an existing device jailbroken at iOS5. Just choose “Jailbreak” again and de-select Cydia (in other words, all the checkboxes will be unchecked). If you are lucky enough to have an old-bootrom iPhone3GS, please pre-select the IPSW first (redsn0w can’t yet auto-detect the FW version of your old-bootrom 3GS if it’s already been jailbroken).
Update #13: With today’s official iOS5 release, redsn0w has been updated to 0.9.9b5 to include the public URLs for the IPSW files. This way, first-time iOS5 jailbreakers don’t need to supply the IPSW file manually. It’s still a tethered jailbreak on all except the old-bootrom iPhone3GS, and it doesn’t apply to iPad2 or the upcoming iPhone4S.
Because the jailbreak is currently only tethered for most devices, we’re not going to release a new PwnageTool yet. Instead, we’ve decided to build some of PwnageTool’s functionality into redsn0w (since you need redsn0w to “Just boot tethered” on every power cycle anyway). The new “Custom IPSW” button on the Extras screen will create a custom IPSW without the baseband update for 4.3.3 or 5.0gm (iPhone3GS and iPhone4 only, for now). Remember to NOT accidentally restore to the stock IPSW after you create the custom one! The custom one begins with NO_BB_ (for “no baseband”). On Mac iTunes, you select an IPSW by holding down the Option key while clicking “Restore”.
You must enter “Pwned DFU” mode before trying to use the NO_BB_ IPSW with iTunes (and your hosts file cannot be pointing to Cydia’s servers due to the new blob nonce mechanism they’re using in iOS5).
[GUIDE] How to Jailbreak Ios[5.0] Using RedSn0w