It's kindofa requirement... to write down what a piece of software you wrote does, becuase no one else is going to understand it as well as you are... but it's still a pain in the ass... especially when you get to a point where you need diagrams, pictures, charts, etc. I think it would be easier if it weren't web software... I could just say "this function calls that function" and draw some pretty arrows and that's that. In webstuff, you have frames and applets and server code and postbacks and all kinds of things happening in all kinds of different places, and it's hard to diagram that in a way that the testing people can figure out to put it through it's paces.
So now, in my semi-sick, mixed-up-mind kind of way, I have to write documentation. This is going to be fun. :P