If You Had All the Money in the World, You'd Have a Problem

In the latest theoretical scenario explored in the What If? series (previously at Neatorama), someone asked "What if you had all the money in the world?" It sounds like a case of wishful thinking, but all the money in the world wouldn't solve your problems, it would just be another problem. First off, it would instantly become useless, because money is merely a medium of exchange, and it's of no consequence when it's not exchanged. The rest of the world would just find some other way to keep track of trade, rendering your "money" worthless. But that would be too simple for an answer in the What If? series, so Randall Munroe and Henry Reich looked at the question from a different direction. Considering cash only, how big of a pile of money would you have, and how would you store it? It's a purely logistical view, but still interesting.