LinkedIn doubled in the first day of its IPO, Facebook is heading to $100 billion before it even floats, higher education might be a bubble, silver had a stab at being a bubble, commodity prices have become uncoupled from demand and China is hoarding rare earth metals. But if you're looking for the perfect bubble, Bitcoin looks like a great bet.
If you don't already know what Bitcoin is, it will take several minutes of reading largely inpenetrable articles to find out. Here's Wikipedia. Here's an explanation from Tim Lee. Here's Tyler Cowen. Bitcoin is a peer-to-peer virtual currency that's better, in various arguable ways, than other virtual currencies like Beenz or e-gold or Azeroth gold coins. A handful of technophiles accept it as payment. There's lots of ways to trade it. It's an internet currency that fulfils the standard criteria for being considered money and you can buy some right now, if you want.