If you’d like to see/hear a side-by-side comparison, I’ve put both videos on this page. The first thing that jumps out at me is how much better the audio is on the Casio, even though it’s using a built-in mic like the Flip. And I think the quality of the video is a little better but that could be a function of how the two device encode for YouTube.
If you want to see the original, uncompressed video from the Flip, you can download the first 30 seconds (35 MB!). It’s not bad. NYT tech columnist David Pogue likes it, too. According to Pure Digital, (the makers of the Flip?) the little camera has 30% of the camcorder market.