Restrict plugins

Hi everyone!

Im new here, so I wanted to ask you guys, since you know alot about WPMU.
I'm looking for a plugin, that can restrict users from certain plugins.

I have like 30 plugins on my WPMU site, but ordinary users can see them all too!
Thats a bit annoying! I want them to see only certain plugins, not them all.

I have been looking all over the web, but I couldn't find anything, anywhere..
Please help me someone...

Best regards
Aris