We have a significantly large (and growing!) team.
I do agree that it's definitely hard to maintain everybody and keep them busy, but we have a team application process in December in which everyone who is interested in joining or re-joining the team applies for a specific sub- field. Here's our 2011 team roster:
http://www.brt1671.com/2011/brt1671/...ters/2011.html
Some sub-teams have a lot of work to do and consistently work on and off season (CAD, PR) and others function when needed (Strategy, Projects). When have people who aren't doing anything label themselves as FAT or Faithful, Available, Teachable and they help do any odd jobs around the shop.