I went to my local Wal-mart to buy Bitcoins and no one knew what I was talking about...however bitinstant.com lists them as a location that I can deposit at to receive Bitcoins. I talked to three separate people there at the service desk and all I got back was "what?" Can anyone help me?

Does anyone know of a website that tracks the progression of bitcoin's richest addresses over time? Ie these addresses were the richest as of month x, these addresses were the richest as of month x+1 etc. I found such a website once but am unable to re-find. Hoping someone in the community might have a suggestion. Thanks!