What other uses are there for pull-back motors?
Yoshihito Isogawa made clock mechanisms from it (well... tic-tac generators) http://www.isogawastudio.co.jp/legostudio/modelgallery_model/b077.html
and http://www.isogawastudio.co.jp/legostudio/modelgallery_model/b078.html.

Majorna created a "programmable" pull back racer http://www.eurobricks.com/forum/index.php?showtopic=69748&amp;#entry1744425

...and another clock by neomomonga: http://www.youtube.com/watch?v=F3-CDFw4O38