This is a stunning picture assembled from photographic data from the Cassini space mission to Saturn and Titan. What is truly remarkable is that the Earth is (barely) visible through the rings (a little Where’s Waldo challenge for you) in this photo.
This picture was voted the best astronomy picture of 2006 here which also shows a closeup of the Earth through the rings of Saturn, just “in case” you couldn’t find it above.
In case you’re looking for a desktop background, the hi resolution source images are here.