Opportunity landed on Mars on Jan. 25, 2004, Universal Time and EST (Jan. 24, PST). It has driven 21.4 miles (34.4 kilometers) as of its eighth anniversary on the planet. In late 2011, the rover team drove Opportunity up onto Greeley Haven to take advantage of the outcrop’s sun-facing slope to boost output from the rover’s dusty solar panels during the Martian winter.
Here is a recent picture from Opportunity
Congrats to all at NASA. You sure can build them 
Here’s hoping Curiosity has an equally long and productive life. It’s gotta land first though. 
No speed demon though, Opportunity’s average is 0.0003052 mi/hour or 0.0004476 ft/sec or 0.0053709 in/sec. That’s about the thickness of aluminum foil per second. To be fair, it did spend a lot of time shivering in its tracks.
If that’s how quickly it moved, then that’s way slower than I thought. Is that the average speed at which it moved when it was actually moving, or the average speed over the entire time the robot was on Mars?
I just divided the distance traveled by the time it’s been there. Here is the website’s explanation of
Rover Speed
The rover has a top speed on flat hard ground of 5 centimeters (2 inches) per second. However, in order to ensure a safe drive, the rover is equipped with hazard avoidance software that causes the rover to stop and reassess its location every few seconds. So, over time, the vehicle achieves an average speed of 1 centimeter per second. The rover is programmed to drive for roughly 10 seconds, then stop to observe and understand the terrain it has driven into for 20 seconds, before moving safely onward for another 10 seconds.
This when you’ve got somewhere to go AND the energy to do it. If you’ve stopped to smell the flowers, your average speed will decline, of course.