In my childhood, we often play pingpong after school and dinner, and in the weekend. It can be set very easily, desk table or dinner table can be used as the pingpong table, some books or small things can be used as the boundary, and sometimes, if there's no partner available, we can play by ourseleves, ping it to the wall:)
I found a 3D ping pong game from the recommendation of widgets group in blogcatalog
I think it's better to put here than in the side bar. so far my best score is 8:11, the competitor is CPU.