Hey there!! I am in the EXACT same market as you right now. I'm looking for a compact digital camera. In the past, i've owned the Casio EX-Z3 and I love all my friends' casio cameras. However, I'm going to go w/ the Kodak V550 instead. Here is my reasoning however if other people have info, tell me! I'm not buying this until tuesday.
The EX-S500 has the Kodak beat in looks and thickness. It is a few mm thinner than the kodak.
However, the black Kodak looks VERY sharp. It has a 2.5" LCD instead of a 2.2" LCD. At first I was very excited by the Casio's 2.2" screen, however, it has the exact same resolution as the Casio cameras with a 2" screen, so you don't get any more information on it. However, apparently the kodak lcd is absolutely gorgeous and has nearly twice the amount of pixels as the casio.
Also, the kodak has an optical viewfinder.
Both cameras can do 640x480 video very well, but the kodak can zoom while filming.
Check out the V550. There are plenty of reviews for it online. Plus, it can be found for as low as $315 online.
In my eyes, the only real advantage of the Casio are its looks and slightly thinner body. If other peopel have experience w/ these cameras, let us know!