userland JB? It's hard to say from here... but either way, don't expect Geohot to release it into the wild. In a mildly jaded blog post, the original iPhone hacker makes it clear that whatever he did here was for his own amusement, and judging by the title of that entry ("Meh") the whole breaking-and-entering bit isn't giving him quite the same chuckles it used to. That's a shame, but we hear the iPhone Dev Team is making progress apace, so let's leave Geohot to tackle one of his other promised hacks, mmmkay?
[Thanks to everyone who sent this in]