The HiRISE instrument on Mars Reconnaissance Orbiter really is a spy camera in space. Check out this sequence of nine images from the HiRISE archives, which Doug Ellison pulled together into an animation covering more than a year of Spirit's mission.
Opportunity is now following a rather leisurely autumn schedule, according to the latest update on the mission website. Some of the work Opportunity is doing involves staring skyward, looking for patterns in the clouds that pass overhead at this time of year. One of the guys at unmannedspaceflight.com has put together some nifty animations of the wispy cloud patterns.
While conversing with Ken Edgett about the smiley face on Mars he remarked to me how different Mars looks at different pixel scales, and in particular that there is a transition somewhere in the neighborhood of six to seven meters per pixel.