If you, like me, struggled through geometry class more than other math classes, or if you never managed to memorize the relationship between pi and sin/cos/tan, you should watch this. Personally, I think that tau is far more intuitive. If I could go back, I would probably use tau for all my math/physics classes and simply do the conversion tau = 2pi as needed.<p>Edit: If this interests you check out <a href="http://tauday.com" rel="nofollow">http://tauday.com</a> for more.