Unfortunately we do not allow members to install plugins, but please tell us what you're looking for, because there's a good chance that we already have the plugin (or another one with very similar functionality) installed for you.
The reason that we do this is to protect our members. All of the plugins that we install are of the highest quality and from reputable plugin developers. They have been tested to ensure the security, speed, and integrity of your site. A poorly written plugin can cause irreparable damage to your site. :)
Let us know what you're trying to do and I'm sure we can help. :)
Our goal is to give you everything you need for your blog to be successful.