German: Useful Site - Wer - Weiss - Was

Hello all, Chris here. Today I have a cool site to share with fellow German teachers:

http://www.wer-weiss-was.de/

I stumbled across this site and thought it has some potential at advanced levels. Essentially the site is a big knowledge base on virtually any subject, similar to http://www.ask.com/. Such sites could serve a dual purpose and one could design activities where students either had to find answers on a specific subject or post their own question and keep track of how many responses they get and how accurately the responses answer the questions. The variety of subjects is of course only limited by the language abilities of your students.

• How would you use such sites?
• Could you design activities for use with these sites for lower-level students?