If you have a smartphone like an iPhone or a BlackBerry, you’ve probably realized that these handy gizmos can do so much more than just keep track of your schedule and make calls. With add-on applications, you can turn your phone into a database of maps, a direct link to FaceBook and other social networking sites, and a handy restaurant finder. Other programs can help you prepare expense reports or find the lowest price on office supplies. Here are some reviews of the best iPhone applications. Later this week, I’ll post some reviews for the best BlackBerry applications.