User blog:Jeff Littleton/Spawn house?

I'm thinking about starting up a multiplayer server, I've done small servers with a friend or two before but I want to make a public one. One thing I really am interested in making though is a spawn house. Like a building that you arrive in when you first log onto the server. One that has all the rules, warps, etc. but I was wondering if there would be a way where the player couldn't get out until doing something or having an admin/user let him out. Any ideas, concerns, or comments?