is giving 0.10btc (currently $1.42) to people that sign up and shit. You only have to verify your account, referring other people is not required.
Bitcoins can be used on the Silk Road
to buy drugs or you can buy legitimate siht on BitMit
. You can use them other places, just google around
Playing the market is always fun, too. Their value has doubled in the past month after the last crash. Right now would probably not be a good time to invest. But they'll be back down to the single digits again soon enough.