WordPress MU

I'm wondering if there's a way to make every blog have to have users register to comment, etc. and remove that feature from their individual user control panels.
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The second part of this is I was referring to an old version of this: http://mu.wordpress.org/forums/topic.php?id=1538

but I'm wondering if this is compatible with WPMU 1.0 (the latest stable release) since I've been following along but so far it's not keeping the setting on the control panel. I've got all the code where it's supposed to be but I can't get the settings to sit permanently.

Any help?
Thanks!

Is there any help with this? I too would like to know this.

Well, first you'd have to hack files. And you'd have to figure out what files to hack and where.

It would be very similar to what's going on in this thread.