Answer Me This...

Just a couple of interesting queries on Quora recently:

1)  "What is the largest non-integer that naturally occurs in mathematics?"

You can see the top answer ("Ramanujan's constant"), and others, here:
http://www.quora.com/What-is-the-largest-non-integer-that-naturally-occurs-in-mathematics

and, even more broadly,  
2) "What is the most intriguing mathematical concept you have ever encountered?"

Of course many good selections for this one, though I was a bit surprised to not see one of my own favorites, "Cantor's dust" or "Cantor Set," mentioned in the responses when I last leafed through them:
http://www.quora.com/What-is-the-most-intriguing-mathematical-concept-you-have-ever-encountered