"Too Close for Missiles -- Switching to Guns."
"Earth First -- We'll log the rest of the planets later."
"Make welfare as hard to get as a building permit!"
"Work harder! Millions on welfare are depending on you!"
"Liberals -- One a day, and one in posession."
"Tact is for people who are not witty enough to be sarcastic."
"Homer, Alaska. A quaint drinking village with a fishing problem."
"Give Blood -- Play Hockey."
"Support Wildlife -- Throw a Party!"
"Complaint Department: 65 Feet Ahead" (Painted on the back of a semi-trailer. Okay, so it's not a sticker, but it IS funny!)
...and for the other nerds and computer geeks...
"There's no place like 127.0.0.1"
"Will work for bandwidth"

(License plate frame)
Marty