Bots, Spiders, and Crawlers: The Results – Manu
manuelmoreale.com/bots-spiders-and-crawlers-the-results
What Jamie wrote
I've long assume robots.txt is ignored by most robots. Moreale's experiment is good proof of that. If you really want to blog robots, you'll need to do it on the HTTP server and it is going to be a big pain.