My fav stat on mars is the number of cameras.

Viking 1 - 2
Viking 2 - 2
Pathfinder - 2
Sojourner - 3
MERA Lander - 1
MERA Rover - 9
MERB Lander - 1
MERB Rover - 9

This is set to increase in '07 with Phoenix which will have 4 cameras (MER augmented IMP = 2, RAC, and MARDI )

As for what the '09 rover will carry - I can only imagine it being at LEAST as many as MER.

If you've got a shovel and a soldering iron, you might like to dig up Polar Landers 4 cameras ( IMP x 2, RAC and MARDI) and Beagle 2's 3 Cameras ( Stereo Camera x 2 and Microscopic Imager. Also comes with cool parabolic mirror for 360 degree imaging with one picture)

There is also the camera onboard the single russian craft that produced a very quick and short-lived data stream that almost certainly contains a view of the martian horizon.

And of course, the many dead cameras of failed russian landers, and orbiters that may have re-entered or burnt up.

But - cameras that have worked on mars, if only for a while, is at a count of 30.