10 Post/24 Hour Rule
This other site I'm on has a "10 Post / 24 Hour Rule" that is reliable at counteracting spammers and bots. We could try to use this instead of the link restrictions.
The site requires all accounts to have 10 posts on their account and that their accounts be registered for at least 24 hours before all of the site's features becomes fully available.
The features that require the 10 Post/24 Hour requirement are:
>Starting new conversations, also referred to as Private Messages. New users are able to receive and respond to conversations started by other users. I think they should also be able to send messages to staff, as I needed to do the same thing when I registered.
>Setting a Signature
>Making Status Messages (like on Facebook)
>Sending messages on other user's profiles (again, Facebook)
On the site, all other features such as posting on the forum and altering profile information can be done by newly registered users without any restrictions.