Run this command to run the image.
docker run --name <yourName> -P icarter09/postgres
The "-P" command exposes the port to the bind port of 5432 in the dockerfile.
Once postgres has started, run this command from another terminal window to access the postgres cmd.
psql -h localhost -p 49153 -U docker
(replace localhost with the IP of boot2docker and replace 49153, with whatever port is chose by Docker....run docker ps -a to find out)
Username and password are both docker.