"One of LinkedIn’s cool, free tools is Signal, which helps LinkedIn users extract more value from the growing amount of content on the careers site and Twitter accounts by helping users slice and dice a tsunamic newsfeed down to a stream they actually can use.
It works like this: There is a “Search Updates” window just under the “What should your network know?” window near the top of the screen. Type in the term you are interested in, and LinkedIn will extract all the relevant messages from its general newsfeed. With 70 million users in 150 industries, there is a lot in that general feed.
When you click after the search term, it will open up a three column-page with the selected posts running down the main central column. Headlines on that subject, passed along by others, are in the right rail. The left rail lets you refine your search further."