Slate hosts Daryl Cagle’s Professional Cartoonists Index and they have a Mars Rover section. I’m a little disappointed that so many of the cartoonists seem to be obsessed with the “amusing for maybe a second” idea of Osama bin Laden being on Mars, or that Spirit is looking for weapons, but some of them are amusing, nonetheless. My favorites are the ones with the Martian border guards, or maybe the ones with Beagle 2.