Funny names for planets:

Venus - Penis. Or to be more PG about it, Penus.
Earth - Smurf.
Saturn - Saturn's Flea Collar. Don't ask.
Uranus - Does this need any explaining? Uranus is a funny planet name within itself.
Jupiter - See below moon*
Pluto - Tooto
Moon - My ass.*

Boys go to JUPITER to get more stupider. Girls go to college to get more knowledge.
--Brings back some good Elementary school times.

*Inappropriate butt funny. Haha. I said BUTT!