Interesting side note: one of the most successful altcoins (a few years ago, back when people cared about this stuff) was called litecoin. The major difference is that it used scrypt instead of SHA because it was hard to parallelize. The idea was this would keep rich groups from taking over the network by throwing money at hashing clusters.

I built a machine in a milk crate that had 5xR9s to mine it. I broke even and sold it after I got bored :) It was fun for a month or two.