- An intellect rivaled only by garden tools.
- An XT clone in a Pentium zone.
- Another engineering prototype that should not have been shipped.
- Answers the door when the phone rings.
- Any slower and he'd be in reverse. -- Gignac
- As a baby his parents stood him on his soft spot.
- As bent as a corkscrew.
- As bright as a nightlight / small appliance bulb / tulip bulb.
- As happy as if he had brains.
- As happy as the village idiot.
- As much use as a back pocket in a vest. (Very English.)
- As much use as a lead parachute.
- As quick as a corpse.
- As rare as a nine bob note. (Very English.)
- As sharp as a marble / bowling ball / beachball / pin head / wet sponge / bowl of Jello / mashed potato sandwich, and twice as smart.
- As sharp as a sack full of wet mice. -- Foghorn Leghorn
- As smart as a politician/lawyer is honest.
- As smart as bait / an automatic email responder script.
- As smart as Christie Brinkley is ugly.
- As thick as champ. (Irish champ is mostly mashed spuds and cabbage.)
- As thick as two short planks / two half bricks.
- As worn out as a cucumber in a convent.
- Attic's a little dusty.
- Back burners not fully operating.
- Bad spot on the disk.
- Baler done run out of twine.
- Bandwidth limited.
- Barney's his hero.
- Bats have flown the belfry, and now he's all alone.
- Bats in the belfry.
