They sound like something out of science fiction, but Bitcoins are getting just a little bit more real every day. They're intangible and invisible, but bitcoins recently attracted some real investment capital from the Winklevoss twins, who first dreamed up the idea for Facebook - or so their lawsuit argued.
A bit of background: Bitcoins are a virtual currency system. They were programmed by an anonymous programmer(s?) in 2009. There are a limited number of possible bitcoins that can ever be traded-21 million-and the "coins" become available incrementally. That process is crowdsourced (anybody can mint bitcoins) but it requires solving complex encryption problems. Most bitcoin miners have an army of computer hardware to do the work for them.