Something that is essentially useless and serves no real purpose, though it initially might appear to the contrary.

Democrat: Well aren't you glad Barack Obama is president now, and we can all bask in the hope and change?

Redneck: Aw, hell, that old boy's about as good as tits on a fish.

The British Military Open Encyclopaedia:

As in "about as much use as .....". However Mr Fish might think different if you ask his opinion of Mrs Fish!

And we happen to think that being trained in the graceful art of the Cold Approach and Social Dynamics by those who have simply read a 7 year old book about the game and had no formal Coaching Training is.......

"About as much use as ....... Tits on Fish!"