I love Rube Goldberg machines. This device doesn't need a specific purpose - the point of a Rube Goldberg machine is to do a simple task (ie, moving a ball from point A to point B) in a complex way.
this is a neat drawing, but it needs to be refined - if the pieces looked more realistic, I'd like it more.
anyone ever play with the ball launcher/Rube Goldberg-esque machine at the Franklin Institute? The photos don't do it justice! It's huge!
http://www.fi.edu/tfi/exhibits/newton.html