Hi there!
First, we don't allow plugins on WordPress.com for security reasons. Plugins are a feature only available for self-hosted blogs provided through WordPress.org. You can find out more about this topic here: http://support.wordpress.com/plugins/
However, we do have several built-in features that were inspired by many popular plugins. You might find what you want by searching for it at http://en.support.wordpress.com/
For more information on the differences between WordPress.com and WordPress.org, please see: http://support.wordpress.com/com-vs-org/
Second, if this is related to your http://capitalismandglitter.com/ site, we are aware of the dashboard issue and please see this thread for all updates:
http://en.forums.wordpress.com/topic/wordpress-error-1