Someone had suggested using a sturdy kitchen table as a pull-up tower (laying underneath grasping the edge of your table and pulling yourself up), however, I don't think mine is strong enough.
You could do some push-ups.... [LOL while diving for cover]
I put a very unstretchy tube with handles over the top of a door, sit on the floor straddling the door, and pull the handles in either pullup or chinup position.