These are a few corny ones I ran across.
Q. Why do sea-gulls fly over the sea?
A. Because if they flew over the bay they would be bagels!
Q. What did the water say to the boat?
A. Nothing, it just waved.
Q. Why don't skeletons fight each other?
A. They don't have the guts.
Q. What did the spider do on the computer?
A. Made a website!