shot a timelapse on saturday of a party at our club, 5000 photos 1 every 10 seconds, but looking back through my libraries my 20d is on 300k shutter actuations and still going strong with no problems yet :)
i tried the hex editor route but was unreliable, i set a filter in aperture across my libraries for 20d and using number of files and sequential file names and made an educated guess hehe
that link doesnt work for the 20d
found this on net
Istvan is correct: only Canon has the software to retrieve shutter cycle information. They can even do it on EOS film cameras. Often Canon dealers will sponsor a "Canon Days" workshop and invites the public to bring in Canon cameras for free cleaning and checkup. They attached a doodad to my EOS 3 and downloaded the shutter cycles into a laptop.