http://doxory.com/ Do x or y lets users ask the site a question, and other users can vote on which choice to make.
http://aimath.org/E8/ A page on the mapping of a large Lie group with links to information about what it is.
http://en.wikipedia.org/wiki/Rumspringa Rumspringa is when the Amish let the teens go and explore life outside of the commune.