Developers are moving closer to an untethered iOS 5 jailbreak every day. Thanks to BigBoss, now you can protect your tethered iOS 5 jailbreak from making your iPhone unusable during a crash or unplanned reboot. The solution to the problem, known as a semi-tethered jailbreak makes it possible for the iPhone to come back up when you can't be near your computer for a full tethered boot.
There are some quirks to the SemiTether package, but having an iPhone that will start up is much better than one that just stays on the Apple logo. You'll still have to get back to your computer eventually to boot tethered for access to jailbreak apps and Cydia. Safari and Mail will also not be functioning when the iPhone is in a semi-tethered state.