The High Resolution Imaging Science Experiment (HiRISE) arrived in orbit around Mars back in the spring of 2006, and is investigating how weather processes and geologic activity have moulded the planet's landscape over millions of years. It is also helping in the search for landing sites for future Mars missions.
The website for suggesting suitable locations is operated by the University of Arizona, and can be found at the following link:
Even if you don't have a location in mind, you can use the HiWish site to look around the planet using previous, less-detailed observations, and find a interesting place that should be imaged. The team will then enter your suggestion into their targeting database, and it may be selected for an upcoming observation.