Quora

First of all, you are probably wondering what it is... Well, quora.com is a website which once you've logged in with Twitter or Facebook, allows you to ask and answer questions as well as find out useful information. Look at it this way, if 'Wikipedia' and 'Ask Jeeves' had a baby, it would be Quora.
Quora was founded in 2009 and made available to the public in 2010. Since then they have also launched an iPhone app.
When you first log in it gives you options of subjects to follow (so when a good question comes up regarding that subject it comes into your main feed) and then it gives you sub-subjects as well. So if you decide to follow Journalism, it then gives you the option of what type of Journalism you would like to follow whether it is Internet or Print ect, ect.
Unfortunately, in my opinion, that is where the good user interface ends as your main feed where all the questions and answers come in to, is overly complicated and cluttered with too much information.
The app is, at best, moderate too.
In conclusion, it's a brilliant idea and it's a great way to learn new information and facts however unless the website design changes so it is easier to see important stuff, I won't be returning to Quora in the near future.