Update.
Cats, like foxes, really seem to have polarized opinion. You either love the little cutsie-pies to bits, or would like to blow the little brutes to bits. I'm slightly surprised that the main annoyance is cat dung. I'm much more affected by dog dung on the way to school with the children.
My affection for cats is not unqualified though. When we first moved to Nunhead, we bought a half-derelict house to do up. Our neighbours had befriended an un-neutered tom which was always spraying its foul scent on the back door. One day it got in through a half-open window and sprayed the bed, the bath, the television, the walls in several rooms and a pile of freshly laundered woolen jumpers. Yeuch. I spent several hours cursing the bloody thing as I tried to clean up. The final act was discovered the next morning when I put some bread in the toaster for breakfast. As the heating elements warmed up the kitchen filled with an acrid gagging stench of mustard gas.