Spinning Color Wheel Of Death

Sometimes I get a spinning color wheel that stops my programs. It prevents me from even using "force quit". I have to turn off the computer via the power button to restart it. It usually shows up when I am uploading pictures at Blogger. What is it telling me the problem is?

I'm on Mac OS X 10.6.8 on a Mac Mini that seems to have 75% memory available.

Run Activity Monitor and see which process is taking over, my guess Flash.

OK I did that. What should I learn by seeing that info?

I'd sort by CPU and see what goes to the top when it beachballs.

Something you are doing is crashing your Mac, you can try and find what that is, and load updates to fix it, or stop doing it.