Horchata de arroz is a wonderful, refreshing, sweet soft drink made from rice, and common in Mexico. It also makes an extremely reliable litmus test for determining the authenticity of a Mexican restaurant. If the restaurant never serves horchata (or worse, doesn’t even know what it is), it isn’t authentic.
This post at Too Many Chefs contains a recipe, and provides the history of horchata, or at least a credible theory about it. There are recipes all over the Web; here’s another one. Or perhaps you’d like to try this receta (Spanish for recipe).
Tasting horchata again certainly brings back memories. I sip it, and am instantly transported to northern México, where I have visited many times, or further back to my [church] bus route in Chicago—my first immersian in Latino culture.