How can i control the plugins i want to be in each sub-site?

Hey
In some on my sub-site i want to use certain plugins (and want other to be invisible)
and in other sub-site i want other plugins..

How can i achieve that?
I do notice that i can do that with the Themes (throw the network site manager menu.. But haven't realized how to do so with the plugins..

Please help me manage the plugins distribution among my sites :slight_smile:

Thanks
Nir