Signing up at matchdoctor is easy and painless - the signup form is very short and easy to fill out. You can be signed up and logged in, in less than a minute. At the end of the signup, they offer a keen membership, but it is not necessary. Matchdoctor has lots of groovy features, like public and private chat rooms, buddy lists, anonymous email, and you can even see who is online on the site and page them to a chat room - very neat. You can search locally by state or zip code.
Message boards are also available.
The number of members at matchdoctor is unknown.