Qikipedia - Instant Wikipedia summary cards on any web page
Anycomplete - The magic of Google Autocomplete while you're typing
Newsit - Find the discussion around the page you're looking at!
Six Degrees of Wikipedia - Find the shortest path between two subjects
Hunter - Find all the email addresses related to a domain
Power Thesaurus - Power Thesaurus is a fast, comprehensive and easy-to-follow online thesaurus for writers...