What is x summarised and where does it fit in the big picture? – Social collaboration: Wikipedia (and other wikis)
What are cool things x; in category y and/or time z? – Social collaboration: Reddit, Digg, Blogs via Technorati or WordPress top list; or RSS aggregation: Client-side (Sharpreader..) or Server-side (Reader, Bloglines..)
(1) is moving closer to (2) and (3) with searchmash.