Thanks for this Paul, I think you've created something that hasn't been recognised for its potential in Spamming Prevention...!
This MOD actually logs activities performed on the registration page, and it is here where SpamBots fail the CAPTCHA image process. What I've
proposed on vBulletin.com, and
requested as a MOD in the Unpaid Mod Requests section on here (I know, I'm skint!) is something that places all new registrations into a table, and from there, the new users can be marked as spammers (for moderation on their posts), or moved into the memberlist should they succeed the registration process.
Your MOD --> Track Guest Visits <-- has a lot more potential than just tracking guests.
Track Guest Visits is my new piece of heavy duty Get Stuffed Spammer kit.
Seriously, it truely is great work.!