When it's going cheep!
Did you hear the one about the crow and the telephone pole?
He wanted to make a long distance caw.
or
Billllyuns and billllyuns. Light bulbs are part of the interstellar "goo" that pervades our universe; they are star stuff.
or
Weeeeeeeeeeeeeeeeeeeeeeeeeee
or
I think I'm coming down with something!
or