Here are some notes from the Michigan Bitcoin meetup of May 22, 2013. They are in no way reflective of everything that was discussed at the meeting; indeed, there's some things here that we didn't talk about at the meeting that I discovered later. But here goes anyway.
1. How does Bitcoin work? I'm looking at the Khan Academy series on Bitcoin and listened to one lecture which seems to spell it out quite well. I don't claim to know enough to describe the cryptographic ins and out here.
2. What can you do with Bitcoin? First, you can mine for new Bitcoins; that's popular, either with GPU-based mining tools or FPGAs or other specialized hardware (this mining hardware comparison is useful). Second, you can use Bitcoin to purchase goods and services, and this Forbes reporter's account on living on Bitcoin for a week is entertaining for a variety of reasons. Third, you can speculate in Bitcoin, hoping to buy low and sell high. Finally, you can build software and systems that help people do all of the above.
3. What are the risks of Bitcoin? First and foremost among those building software and systems, the problem is uncertainty of regulations, especially dealing with money laundering and financial crimes rules. The recent document "Application of FinCEN's Regulations to Persons Administering, Exchanging, or Using Virtual Currencies" from March 2013 will need to be studied and pondered by everyone involved. The Washington Post (among many others) reported on Mt. Gox's troubles with FinCEN and the seizure of funds from their account. There are also technical hurdles, such as the vulnerability of exchanges to denial of service attacks and the recent wild fluctuations in Bitcoin exchange rates.
4. How is this different from other virtual currencies? (I'm thinking now Beenz, Flooz, Linden Dollars, Cybercash, Digicash, and the like.) See US News "Six virtual currencies that went bust".
5. Where is the action? In Ann Arbor, there's a startup exchange Bitbox. In Berlin, there's the Kreuzberg district, with shops that accept Bitcoin (so says the Guardian). The Winkelvoss twins are in on the business. San Jose was the home of the conference Bitcoin 2013. Things are hopping all over the world.
That's not really a summary of the meeting, but it's a summary of the things that I didn't know before that I now know a bit(coin) better.