Yes, everything mechanical has a life span.
Here is a link to shutter life on an EOS 20D
http://www.olegkikin.com/shutterlife/canon_eos20d.htm
The shutter actuation count is embedded in the raw CR2 file. Once you open the raw file in a hex editor you can find out the shutter count. Here is the link.
http://www.flickr.com/groups/canon20...7594389608272/
I am going to see how this works.
Cheers,
Tim