Some random web surfing tonight led me to the site Find a Grave, which bills itself as the "world’s largest gravesite collection". The site allows you to search for cemeteries and grave records for regular and famous people or create/add to virtual memorials, if you register.
Another option is to search through a specific cemetery's page and find out a little about its history and the famous people who are buried there. There's a page of interesting grave monuments, and another for interesting epitaphs. People who register can make requests for photos of their loved one's graves, or can upload photos to fulfill requests.
Five years ago today: San Fran