Roamy here. NASA Science News has an excellent article on the yearlong radio silence and the end of the mission for the Spirit rover on Mars. What was originally planned for a three-month mission extended over six years, with a tremendous amount of data returned. The rover started dragging a wheel then was stuck in sand and unable to get out or turn its solar panels directly towards the sun.
Spirit did take the first picture of Earth from the nightsky of another planet.
Its sister rover, Opportunity is still trundling across the surface of Mars and just recently rolled over 30 km (18.64 miles) on the odometer. I’m sure the scientists plan on driving that one until it, too, goes dark.