Confused 3GS owner

[jeffw78]

So I have a one month old 3GS on 4.2.1 with a baseband of 05.15.04. From what I gather, I can jb with redsn0w right now and be tethered. My questions are
If my battery dies and I turn phone on, is it usable at all until I tether and reboot again?
Will I be able to update to an untethered jb when available??
Sorry if this is basic knowledge. New to iPhone and jb'ing. But anxious to try it out. If it makes a difference; my phone is a 8gb

 

[farbod21]

A tethered jailbreak in and of itself will not render your phone inoperable if booted without the tether. However, if you have any apps or tweeks using mobile substrate or using features of the springboard, then yes it will throw you into a reboot loop.

When the untethered JB is released, you can backup, restore to fresh 4.2.1 and rejailbreak

 

[jeffw78]

Thank you. Guess I'll give it a shot.