Thomas Schilling
I would advocate using a comment system that is similar to the one at http://djangobook.com/.
I'm pretty sure Brian O'Sullivan has written a Haskell implementation of this for the Real World Haskell book.
While the technology is there (or will be), I worry if this is the right solution for something else than soliciting comments on a (fixed, non-editable) text. I can all to easily imagine a situation where any documentation is riddled with a plethora of notes, questions, answers, comments etc, with nobody to clean up the mess every now and then. For user-edited documentation, a wiki seems a much better fit - where each author make some effort to leave pages as self-contained consistent documents. -k -- If I haven't seen further, it is by standing in the footprints of giants