It was an inevitable face off. The iPhone 3GS and the Flip Mino HD. One of our readers, Adrienne, did just such a test at the Dayton airshow July 18-19, and held the two cameras together to see how they compared.
Turns out both do well, with the Mino having higher resolution, of course, and the iPhone getting smoother video with less pixels to push around.
A summary of the results:
Video Comparison: iPhone 3GS and Flip MinoHD
Summary: the Flip Mino HD obviously has a much higher resolution at 720p compared to the 640x480 video of the iPhone 3GS. The biggest discovery for me was the field of view on the iPhone is much wider. The iPhone has been great for capturing video of the moment up close but it's not the right tool for capturing something like this airshow with subjects of interest much farther away. For that you'd need to add on one of the external zoom lenses that are starting to appear. Of course, once you start adding other things to the iPhone the key benefit of easy to carry and always with you starts to diminish.
One more observation that may not make it through the processed video -- the iPhone video actually appears a little smoother with high motion pans like those in this video (I'm guessing the reduced data rate has something to do with it).