Taken from...
"1000 Ways To Call Someone Stupid... "
Couldn't hit sand if he fell off a camel.
Couldn't hit the broad side of a barn if he were standing inside.
Couldn't hit water if he fell out of a boat.
Couldn't organize a piss-up in a brewery.
Couldn't pour water out of a boot with instructions on the heel.
Couldn't run out of sight on a dark night / in a week.
Couldn't scratch his ass with a hand full of fish hooks.
Couldn't tell which way the elevator was going if he had two guesses.
Couldn't think/pee/fight his way out of a paper bag.
Couldn't walk on water at absolute zero.
Couldn't write dialog for a porno flick.
http://www.insultmonger.com/insults/100 ... dity_3.htm