NASA has released a Mars Panorama, which it calls the "next best thing to being there." The panorama
was assembled from 817 component images taken by the panoramic camera (Pancam) on NASA's Mars Exploration Rover Opportunity between Dec. 21, 2011, and May 8, 2012, while Opportunity was stationed on an outcrop informally named "Greeley Haven." You can see a large full-res JPEG version of the panorama here
Jim Bell of Arizona State University, Tempe, Pancam lead scientist, says, "The view provides rich geologic context for the detailed chemical and mineral work that the team did at Greeley Haven over the rover's fifth Martian winter, as well as a spectacularly detailed view of the largest impact crater that we've driven to yet with either rover over the course of the mission."
You can find more Mars panoramas created using images taken by the Mars rovers here
Photo: NASA/JPL-Caltech/Cornell/Arizona State Univ