Check out the Zgrip iPhone PRO by Zacuto. The fully articulated arm holds the iPhone in place and several adjustable pivot points allow you to get interesting angles. We haven't played with one, but it sure looks pretty cool. Before you scoff, check out what some people have done with video on the 3GS. The Zgrip iPhone PRO is available now and costs $295US (a low-cost consumer version is forthcoming).
[Via Coudal Partners]