Interacting with people is fun, and this guy manages to engage crowds of people to go dance walking with him. This really brings a smile to my face, especially since people starting to dance spontaneously still has a Bollywood-like quality in my eyes:

Leaving notes with Truth or Dare questions in public places is also fun.

Still, I like the first idea better because there the guy is actually willing to go out there and make a fool out of himself, while the truth or there feels kinda cowardly in a sense.

How much is a billion?

It has always been confusing to me that a biljoen (in Dutch)  translates to a trillion in (American) English. This video nicely explains how the different systems came to be (and of course the narrator thinks our system is better :P).

Gopher tuna

I love Carl Orff’s Carmina Burana, but ordinarily it sounds quite severe. With misheard lyrics O Fortuna turns into something completely hilarious though: