Juice, is an on-demand web service built on intelligent discovery for rich and contextually relevant information for web users.  To translate that down to people outside of the PR world – it is a nice search engine, with perks.
The add-on for Firefox will continually run in a sidebar, and can be activated by selecting a chunk of text and dragging it over to the sidebar.  You then get tons of information about that person, place, thing you are searching [...]