From Seamster's super creative Instructable:
"This is a tabletop pinball machine made from all scrap wood and bits and pieces of things I've held onto just waiting for a project like this. The ball is from an old computer mouse, with the rubber coating removed (you could use a marble as well). A crafty person should never throw perfectly good stuff in the trash. Just hang onto it, and eventually you'll find a new use for it down the road!"