You don't need to search to find a useless definition on this site.

Gayrab: "I"VE BEEN SKATEBOARDING SINCE 1964! YOU ARE A KOOK! I'VE BEEN RIDING THE SAME BOARD FOR 18 YEARS! I CAN'T KNEESLIDE AND I HATE SKATING ON WATERFALL SHAPED BOTTOM POOLS!"

Jack: I'm scared to think, can you decide things for me.
Gas Sation Attendant(GSA): Didn't you just graduate from college?
Jack: Yes I have a college duh-gree.
GSA: Ah, I see. Ok. You gave me $20...
Jack: Yeah, thats a twenty dollar bill, right?
GSA: ...and you put $16.50 on pump 11.
Jack: Stop. Just give me my change.

Chris, ever since you got a girlfriend you have been absolutley useless

TA is useless because he typed the word 'obbject'

Oscar is so useless that he has trouble even screwing in a light bulb

the lady from the book "so much to tell you"
a person who is both a blind and deaf mute and also missing all limbs is preety useless in the sense that they cant do anything. they cant; read brail because they have no hands, see, hear or speak to anyone, walk as no legs are attached to their abdomen. The best they can do is to hold a cane in their mouth in hope that their wheelchair doesnt get munted into a wall and there cane be forced down their throat.