It seems that specs are like flossing: everybody knows they should be writing them, but nobody does.

Another for the wish I had said that list. Joel Sposky wrote a four part series on writing functional specifications in Oct 2000. Joel’s opening position is that all projects lasting more than a week, or with more than one developer, will be completed faster with specs than without them. He presents three giant reasons to use a requirements document as part of developing software
Three Giant Reasons