An idea I had: New user sponsors
Basicly when a new user signs up there is an optional field where they can put in the member # of the user who invited them or referred them to the forums. Using the member # is the only way I think it can be done because display names aren't always the same as login names, plus it's simpler.
That way you can offer incentives to existing members to go out and refer/invite new members. You can add a field in the user profile to include the number of refers.
With this feature you can give all sorts of reasons for existing members to want to go out and invite more people. Say for instance, just like the user titles, at each level of referred/sponsored users they can get some prize or special privelege. One example is the custom title hack. If that could be perhaps integrated into threads, but only be turned on to users who have a certain number of referrals. I figure the possibilities are endless.
I imagine this could be a real shot in the arm for community involvement <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" /> Obviously to be taken seriously new users would have to verify their accounts through email and only one user per email address (something most threads administrators do anyways). In fact it could be made that new users who had a sponsor have to get to a certain minimum number of messages before they count towards their sponsors total of referred users. This keeps the board from filling up with phantom users who were created by the same person who sponsored them.
A nice thing would also be able to set a minimum number of messages (or perhaps user title) from the admin section for an existing user to become a sponsor. Say for instance only users with 50 posts or more can be a sponsor for new users. Obviously it would require some tweaking, but it would be a really cool feature.
BTW: I didn't put this in 6.3 suggestions because I didn't see this as being a feature that could be ready by 6.3 <img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />
