I've seen some game trailers that were not just camera phone videos of a phone while someone is playing it.

Are there tools to help capture game play video?

Highly recommend Screenium if you're on OSX.

http://www.syniumsoftware.com/screenium/

For the PC try Fraps for recording videos and Windows Movie Maker for editing the videos.

I have Snapz Pro for the Mac which will capture screen video. The problem is my game uses the accelerometer for movement which I can't emulate on the Mac very well.

Is there nothing to capture video from the device itself?

I guess I could program up a quick demo mode and have the game play itself.

I ended up going the demo mode route. It was much easier than I thought it would be.

Find the X of the first target in the list, transition my X to there, drop in some easing to make it look natural.

I used SnapZ Pro and I didn't have any problems.