Thanks to the folks at Aquarium Advice this guy has been identified as Stomatella Varia and is member of the Mollusca Phylum in the class of Gastropoda. We found him first on the live rock but had a hard time photographing him as he is small (about the size of a raisin), and well camouflaged. We didn't see him for a few days but then discovered him on a group of coral in the tank so I popped him is a small plastic tank to get a better photo. According to one article at Reefkeeping.com, because of Stomatella's lack of shell to hide in, it has developed a unique ability to "drop" it's hind quarter like a lizard while it scampers away.

Another freebee

Every once in a while you hear on the news that some undiscovered species has been found some where in the world that excites the scientific community. If you like that type of adventure, buy a saltwater aquarium. If you have the patients to sit and stare at a tank, you'll find yourself eventually saying "oh my God, what the heck is that!" This guy is really hard to see but I'm guessing it's some sort of limpet. It has a pseudo shell and it's has a body and antennae like a snail, and I assure you, I got it for free somewhere.