Garageband on iPhone?

Forgot to post this from the other day... someone's dreaming of Garageband on iPhone. Not sure if this is (a) feasible, or (b) practical, but it would certainly be cool to be able to use the iPhone as a podcast recording device. It would require a dock connector gizmo that could hook up to a decent microphone (or mixer). Might be nice to haul the iPhone around rather than a laptop for mobile recording...