Redsn0w 0.9.10b6 iOS 5.1 jailbreak for all non-A5 devices (Tethered)
As you know, any iDevice prior to the iPad2/iPhone4S is susceptible to the limera1n bootrom exploit. Because of this, no matter what new firmware Apple releases, these devices will ALWAYS have a tethered jailbreak available. Today @musclenerd has released Redsn0w 0.9.10b6 to perform a tethered jailbreak on these devices.
Simply download redsn0w, run the jailbreak section as you normally would and then after the jailbreak process has completed you can re-open redsn0w and go into "extras" and select "just boot" in order to boot your tethered device. Remember that this does not apply to the iPad2 and iPhone4S. If you are on an A4 device or lower, you can always downgrade back to 5.0.1 as long as you have your SHSH blobs saved, so if you want to upgrade to give the 5.1 jailbreak a shot, go right ahead!
Those who require an unlock, be sure that you create a custom 5.1 firmware with Redsn0w to restore with. If you restore with a factory 5.1 firmware file you will update your baseband and lose the ability to unlock.