Well, Saturn is also visible. It's over by Regulus in Leo. Okay, the pics don't look great when they're small like this... It's a short exposure and there's light pollution. Click on it to get a bigger version.
Saturn is farther away than Mars, so it's motion against the background sky is not as noticeable. But if you pay close attention you'll see Saturn starting to drift away from Regulus.
Image details... Camera: Canon 20Da, f/5.6, ISO 800 Date/Time: 5/4/2008 9:37:33 PM Exposure: 8sec Lens: 17.0 - 85.0mm at 35.0mm