The free-content encyclopedia that anyone can edit.Sooner or later I've got to cover all the really big content sites we all know and love. I thought today was a great example of the power Wikipedia can harness because of the incredibly complete London bombings article that's been compiled today.
For those of you who haven't heard about or used Wikipedia it's an amazing source for knowledge on pretty much everything.
English Version: http://en.wikipedia.org
All Versions: http://www.wikipedia.org