This page in the application lists all plugins which specify weblog-level configuration settings (as opposed to system-level plugin settings).

If you have permission to configure the weblog (i.e. configure weblog permission, blog administrator or system administrator), you will see plugin settings links which allow you to configure how your installed plugins act on that particular weblog. See "Author permissions" for more on permissions.

Again, if you are looking for a full list of plugins installed on the system, go to the System Overview » Plugins section of the application.