In this talk I'll describe what Bitcoin is, how and why it's used, and how it works under the hood. I'll also show a live demo in Linux of bitcoind, pooled mining, and Namecoin (a distributed DNS). If you are completely unfamiliar with Bitcoin there's a short overview video at http://www.weusecoins.com - if you *are* familiar with Bitcoin, please feel free to speak up during a Q&A at the end!