The Choc-U-Lator Makes Math Tasty

I hope it doesn't melt in the sun otherwise this will just end up in the same 'as useless as' category as the chocolate teapot and the chocolate fireguard.

Chocolate teapot! I like it. One of the guys in the workshop has a saying: "As useless as a one legged man in a butt kicking competition."

Another favourite: "As blind as a welder's dog."

as popular as a fart in a space suit

There are some great expressions around , but what about the odd ones;

"I need this like a hole in the head" - ? Most of mine are fairly useful (others may disagree!)

"I'm sweating like a pig "- They don't sweat (I'm told ) ?

"My feet are killing me" - that's downright scary.

" He's a pain in the arse" - how would you know ?

etc etc