I've flown quite a bit with a camcorder lodged in the corner of the windscreen with a piece of rag, pointing out of the front. Gets nice results for mountains, passes, approaches etc without any danger of being distracted - just leave it running for 3Hrs and then edit the 'good' bits on the computer later.
One thing I've noticed is that when you step through the frames later each alternate frame is clear, blurred, clear and so on. Took a while to realise this was the prop sweeping through the field of view!
One of the best uses for a camcorder is to choose individual frames for Internet stills. No matter how hard you try, you never seem to quite get the right shot with a still camera. Here's one I did earlier:
