There are many ways to listen to the crowd and what they are currently learning or in what subject they have an interest.
One place to start your journey are the Google Hot Trends: Every hour the top 100 search terms are listed. http://www.google.com/trends/hottrends/atom/hourly
Here some interesting examples:
1) Academic Earth: Get free 24 lectures on astrophysics http://academicearth.org/
2) US National Debt Clock: Want to know how how much the current debt load increased for each day: http://www.usdebtclock.org/
3) You want to follow Discovery launch online ? http://www.space.com/spaceshuttle/