A classic top 10 list from Mr. Letterman of the Late Show on CBS

From David Letterman...
Top Ten Most Polite Ways to Tell A Guy His Zipper Is Down

10.)  The cucumber has left the salad.
9.)  Quasimodo needs to go back in the tower and tend to his bells.
8.)  You need to bring your tray table to the upright and locked position.
7.)  Paging Mr. Johnson... Paging Mr. Johnson...
6.)  Elvis is leaving the building.
5.)  The Buick is not all the way in the garage.
4.)  Our next guest is someone who needs no introduction.
3.)  You've got a security breach at Los Pantalones.
2.)  Men may be From Mars.....but I can see something that rhymes with Venus.

And the #1 way to tell someone his zipper is unzipped.....

1.)  I always knew you were crazy, but now I can see your nuts.