@Jeffro - Controlling post revisions isn't something most people will want. Remember that while you may not be a programmer, you are still a power user of WordPress and most users will not care about the size. People I've helped in the #wordpress chatroom are grateful for the fact that they can revert to a previous version and that it's built in. But, I will have to agree to disagree on this one. :)

@Andrew - If your host has arbitrary limits on database size, you should be looking for a new host. Most hosts limit the number of databases you get, but never the size of the databases themselves.