Has anyone ever made Horchata? It's a rice milk drink from Southern Mexico, a type of Aguas Fresca. It usually consists of the following ingredients:

1 cup uncooked long-grain white rice
1/4 cup raw almonds
1 cup evaporated milk or water
1 cup white sugar or cane sugar (panela)
a couple pieces of cinnamon bark (canela)
1 vanilla bean, scraped

What ingredients do you use, and how to do you prepare it?