At the time of this writing, this program should work on all DIGIC III and IV cameras EXCEPT for the 1D and 1Ds. The author, Astrojargon, believes it should work on the Canon EOS 5D Mark II, but until someone actually receives one or tests this program, we wont know for sure.
Reading his FAQ #7, he says that most people believe this number to be correct. Well, you can add me to that list as well. My last image (a picture of Rhys Millen standing on the podium aftering winning $25,000 from his 1st place victory at the Red Bull Drifting World Championship) was numbered 9612. Astrojargon’s “40D Shutter Count Version 2” reported 9613. Its off by one, but he mentions that if you actuate the shutter without a CF card, then the IMG_XXXX would not incremement, obviously. This, I can confirm, is my case (I left the house once without a CF card and tried to take a picture before realizing I didn’t have a CF card in the camera).
Anyway, enough BS.. you can find his program here: