This just in, by e-mail. Not up to our usual standards, but worth quoting.

The wheel's spinning, but the hamster's dead.
The lights are on, but nobody's home.
All foam, no beer.
The cheese slid off her cracker.
Body by Fisher, brains by Mattel.
Couldn't pour water out of a boot with instructions on the heel.
As smart as bait.
Chimney's clogged.
Doesn't have all his dogs on one leash.
Doesn't have all her cornflakes in one box.
Elevator doesn't go all the way to the top floor.
His antenna doesn't pick up all the channels.
Missing a few buttons on his remote control.
No grain in the silo.
Receiver is off the hook.
Skylight leaks a little.
Slinky's kinked.
Not the sharpest knife in the drawer.
24 cents short of a quarter.
A few feathers short of a whole duck.