If you’ve ever been curious about your camera’s shutter count (or maybe you bought a used camera), then the EOSInfo utility might be something you are interested in.
Check it out here.
There’s a few caveats like it only works with DIGIC III and IV DSLRs, 1D series cameras don’t work with it, etc. Read the fine print and disclaimers before you jump head first into this stuff.
(h/t to Canon Rumors)