Go to this website:
http://astrojargon.net/EOSInfo.aspx
Download the installer there.
Connect your 50D to the computer and run the program. You should get the shutter count there. it works well for my 40D and the website say that it will work for 50D as well.
Hope it helps.
As for someone asking for 600D shutter counts (I think). This camera is pretty new, so no software out yet.
Another way was to bring down to CSC to check.