Ian Betteridge’s lifestream

"Just enter a search query as you always have, and see new results instantly stream in at the top of your screen in real-time. No need to constantly click refresh. It's an extremely useful (not to mention mesmerizing) way to immediately see what people are saying about a particular topic. You can search across just your friends or all of FriendFeed, including imported services like blogs and Twitter accounts."

Real-time search is a really useful feature for news junkies and anyone who has to monitor a specific topic for work or play. And FriendFeed searches are powerful, too, with a level of granularity that makes them incredibly useful.