Marcus (aka @msykes)

=THIS PLUGIN IS ONLY USEFUL IF YOU’RE USING MULTI-SITE MODE=
This is the same plugin previously available at <a href="http://firestats.cc/wiki/WPMUPluginCommander" rel="nofollow ugc">http://firestats.cc/wiki/WPMUPluginCommander</a>, which has been used reliably with wordpress multi-site networks for many years.
Plugin Commander is a plugin management plugin for multi-site mode, which allows further control on network-activated plugins.
It allow you to do the following things:
<ul>
<li>Mark any plugin in the plugins directory to be automatically activated for new blogs.</li>
<li>Mass activate or deactivate a plugin for all existing blogs</li>
<li>Choose which plugins users can activate and deactivate through Manage->Plugins, for this to make sense you need to disable the built-in plugins menu (through Site Admin->Options->Menus)</li>
<li>Activate and deactivate plugins for specific blogs, even if the blog owner is not allowed to control those plugins.</li>
</ul>

Plugin Commander

Plugin Commander is a plugin management plugin for multi-site mode, which allows further control on network-activated plugins.

fritsjan

With this plugin you can simply batch create / add a bunch of sites to your WPMU install (WordPress Network) and use one of your existing sites as a template for the new sites. The existing blog will be cloned exactly including posts, layout, settings, etc. The plugin also takes care of domainmapping the newly created sites. (depends on ‘WordPress MU Domain Mapping’ by Donncha to be installed)
This plugin will save you a lot of time. 
Even adding one site is faster with this pluging compared to the normal way: add site, domainmap it, set everything up.
Update: You can now also use it without domainmapping, so just cloning sites in a batch! Insert the name of the subdir or subdomain you want to make in the place of the url.

Add Clone Sites for WPMU (batch)

Batch add new sites on Wordpress MU / Wordpress Network while using a template site to clone, includes batch domainmapping of the new sites.

Plugin Commander vs Add Clone Sites for WPMU (batch)