John,
Good post. I do the same thing and try and answer what I can. Have had great responses and some great conversations with people. Only one negative response from a woman asking for unit information - wrote her and she wrote back saying she didn't 10 people writing her to tell her this info !!!!! So on the good side some others must be looking on the guestbook as well.
Just avoid cranky geneologists !
Best wishes,
John g.