WordPress MU

Is there a way to limit the number of blogs that can be created on a given mu installation? I'm not talking about limiting a specific user, but the entire installation. Once the limit has been hit, the signup form won't accept any more signups until a blog has been deleted (how that error would be handled specifically is unimportant at the moment).

I know edublogs has the premium thing and it appears to have limits, but are those separate installations or some kind of sub-installation within a master installation?

You probably could code something fairly easy. Just do a check against the wp_blogs table to see if you've reached your limit.

Hmm, yes, I was just hoping somebody had already done it so as to avoid reinventing the wheel. I see there is a function get_blog_count(), but I can't seem to find a place where it's actually used. Or at least where the results are displayed.

Looks promising anyway, so I guess I'll just start hacking up my signup page and see what I can break.

Thanks.