iPhone Dev team has release second beta of Redsn0w 0.9.7 to do untethered 4.2.1 jailbreak on iPhone 4 & iPod Touch 4G & iPad. The Redsn0w 0.9.7b2 fixes all the app crashes and should strictly used by expert users having MAC OS X & saved hashes for iOS 4.2 b3.
Here is what iPhone Dev has to say,
Update #2: The second beta is now available (testers ONLY please!). This version should fix all the native app crashes (including Task switcher). That’s the only change in from beta1….Bluetooth is still disabled. If you had trouble using the usbmuxd in beta1, please wait until we incorporate that into redsn0w itself (i.e. don’t bother trying this beta2, just wait for the integration).
The download link is:
Redsn0w 0.9.7b2 (OS X). Please test this after a fresh restore (otherwise it’s impossible to keep track of the variables involved). Select “Jailbreak Monte” to try out the untether.