We all know bitcoin. But there are hundreds of other cypto-currencies out there. Doge, Lite, Dash, even a Cannabis coin. There are many exchanges out there but I have found one that I really like where you can easily trade in all the other currencies. It is called Cryptsy.  You can easily create online wallets and transfer and trade in other coins. They have a pretty decent amount of volume in there trades so you don't get stuck holding something you don't want or want to get rid of.  They appear to be large and stable exchange. So give it a try. Again Cryptsy.