Do you understand bitcoin? If not, or even if you do and just want to learn more, check out Wired's Bitcoin Survival Guide. I've gone from thinking it's a weird fad to thinking there's something to it to thinking it seems to be getting traction. It reminds me of much of the backstory for Neal Stephenson's classic Cryptonomicon, the desire for a currency which doesn't need a central administration to regulate it or establish its value. Long term this would be pretty compelling; short term, we'll see if the [in]stability of bitcoin holds up.
For more, you might enjoy Bitcoins Bitcoins Everywhere, from Brad Feld, which has a bunch more links...