Absolutely! For folks who are technical enough to care about ssh'ing from their iPhones, a jailbreak is such a no-brainer. There's so little cost involved in it now with QuickPwn and stuff..

I personally don't jailbreak because

1) It's my main form of communication 2) Apple killed jailbroken iPhones once, they could do it again 3) I can't afford to buy an un-subsidized 3G iPhone yet.

When any of those three changes, I'll jailbreak; 'til then, I'd rather pay a few bucks and keep warranteed reliability.