When I'm not around for a weekend, about 500 spam bots register on the forums. It's insane.
I know the feeling. I have deleted over 20 000 of them off the SliTaz Forum, but there are still 200+ registrations every damn day.
(Sorry for the delay in my answer...)
Would the player select his answers or write them herself?
-> I mean the player could choice his answers.
500 newcomers a week ? How lucky ! ; )
Text parsers are a bit of a pain, but you could probably do something similar to ELIZA to pull it off. Won't work very well for words it doesn't know and you can only flip an answer so many times before a human figures it out. The alternative is to go the Digital: A Love Story route and have assumed responses from the player.
Man, migrating the forum was a pain in the ass. But I kinda like how it turned out... minus the few import mistakes.