Here's an app that lets you browse through the popular link board Reddit. You probably don't want to see everything there is on Reddit -- just like Digg in its day and other message boards like 4chan, some of the discussion over there can get pretty wacky. But Reddit is definitely a great community of people, and if you ever want to take the temperature on what the 'net is thinking about the news of the day, browsing through Reddit's links can be very informative.
There is an official Reddit app called iReddit, and it works pretty well. But Alien Blue is really the better option. I like the layout better,