They were only meant to last a few months on inhospitable Mars, but on January 3rd 2007, the Spirit rover will incredibly begin its fourth year of operation and a few weeks later so will Opportunity. Both rovers have survived many trials, such as jammed wheels and dusty solar panels, but they are also getting smarter thanks to software upgrades beamed to them from Earth. Newly added for 2007 is the ability to pick out significant changes between images, a very useful capability in the search for dust devils. Both rovers have snapped dust devils on Mars, but with the new software, they will be able to pick out the fast moving weather features and beam those specific images back to Earth, saving much bandwidth. Similar thinking will also help the rovers spot interesting cloud formations. Several other upgrades to give the rovers greater autonomy have also been added, and this unexpected chance to test new ideas in live laboratory conditions is sure to provide useful experience for mission planners working on future missions. A detailed review of the upgrades can be found at the spaceflightnow site.