I set up the video camera tonight to capture the sunset. The result was pretty striking, but the camera's auto focus feature kept losing track of what it was looking at and the end result was a video that would have made you nauseous if I had posted it as it went wildly in and out of focus.
Back to the drawing board! I'll try and get a good one some time this weekend.
Update: My little Canon ZR800 has a manual setting for focus and I can tell it to focus permanently on infinity for the video. Problem solved! Sunset videos are in our future.