Facebook began trading on the stock exchange today and that's how much Mark Zuckerberg's shares are worth. That's roughly 641,786,840 hoodie sweatshirts.

And he's not the only billionaire in Facebook-land.  According to CNBC, Facebook co-founder Dustin Moskovitz is sitting on $5.1 billion, former Facebook president Sean Parker has $2.6 billion, co-founder Eduardo Saverin with $2 billion, and Facebook COO Sheryl K. Sandberg owns about $1.5 billion in Facebook stock.

It's funny to imagine how one website that allows people to vent about life and post pictures of fuzzy puppies is now a $100,000,000,000 internet empire.