My brother showed me this website awhile back and they just recently added some pull screen quicktime panoramas from Mars. Currently they have 2 from the Spirit rover and 1 from the 1997 Mars Pathfinder mission.
Mars 1997 (very cool)
Mars 2004 (color) (On this one if you click the hotspots on the bottom left it will show you some interesting locations on Mars.)
Mars 2004 (Black&White)
Warning: These may not load very fast on 56k, but I do not know for sure.