As this is a small site with only a couple of new registrations per week, I have operated a manual check and approval process since I took over from John. All new registrants are checked against the database at
www.stopforumspam.com for username, email and IP address.
The process isn't perfect as the database relies on people (forum owners) adding new spammers as they are discovered. Spammers have changed their modus operandi and now do mass registrations and wait awhile before going back and spamming - that way they don't appear on the database until it is too late!
However, those poor sods who's job it is to register on forums all day are fairly simple in their choice of username/email and most stick out like a sore thumb!
Each times there is a registration I get an email to remind me to go and check/approve the newcomer.
This morning there were 24 waiting for me, so have deleted them and switched off the system for a while.
So if you are Mr LedGypeimmity (or various small variations of such) - unlucky.