Joe Gregorio builds a Python Web framework in 60 lines of code. One thing I particular like is the use of Selector:

import selector
import view

urls = selector.Selector()
urls.add('/blog/', GET=view.list)
urls.add('/blog/{id}/', GET=view.member_get)
urls.add('/blog/;create_form', POST=view.create, GET=view.list)
urls.add('/blog/{id}/;edit_form', GET=view.member_get, POST=view.member_update)