Why not have the kids make the power point? They are more tech savvy than most of us. I do have powerpoints but they are very extensive for each time period because I taught AP Art History. They took me many hours and one year of working every night to put together. If you give your students a timeline, or the Metropolitan museum of Art's website that HAS a time line, they could put together a brief art history ppt, and would learn in the process. Also if you don't have "computer time" in your school, this could be assigned as homework. Very few kids don't have access to computers anymore because their public libraries offer computer time.