Maestro lets you control a virtual Spirit or Opportunity. The site claims the software is a scaled-down version of the software actually used by NASA. Here’s what Chapter 1 of the Online Manual says:
Maestro is a publicly available version of the tool used by scientists to plan daily activities for the 2003 Mars Exploration Rover mission. With Maestro, you can view pictures taken by the rover. You can also select driving destinations and points of interest where you want to take your own pictures.