Is there a signature size limitation? I haven't tried to post one yet, so I don't know.
I've always been a fan of signature limitations though. Banner sizes like 600 pixels wide by 100 pixels tall are typically good. I know vBulletin supports it.
Another cool thing some vBulletin software supports are signature badges. These are little graphics assigned by certain people to represent different things. They are not put into a signature by the the board member, but typically a Moderator.
We use them on
www.s2ki.com to designate which local community someone belongs to or whether that person is good at car care, audio systems, forced induction, photogrpahy, photoshop, etc....
We also have "Community Organizers" who take lead roles in the local forums to promote meets and the community in general. It would be great to see that same sort of idea make its way here - the "Zones" seem stagnant. Maybe changing the names from "Zones" to names that depict the area could help too?
Last thing Ken - I know you're still in the process of building this site, but before you call it finished, take a look at
http://www.s2ki.com. In my opinion it is the best setup vBulletin site and has its own look and feel in every aspect. I'm not vouching for the content, but just a place to grab some ideas from. I haven't had my S2000 for a long time, but I am still a moderator there because I love the site and my local S2000 community is incredible.