marina phillips wrote: What about agave "mead?" Like, tequila wine? I bet it would be good, I don't know for sure yet but I bet it's a common brew in the appropriate geographical regions. Fermentation is always where my mind goes. 
Well, You are correct! Pulque is made from Agave sap (before syrup, I think). I had a 6-pack of it that was
terrible, but I've never had the traditional stuff. You'd probably have to go to Mexico to find it. Doesn't ship/store well -
"Just before the peak of fermentation, the pulque is quickly shipped to market in barrels. The fermentation process is continuous, so the pulque must be consumed within a certain time frame before it spoils."
"Pulque is a milk-colored, somewhat viscous liquid that produces a light foam. It is made by fermenting the sap of certain types of maguey (agave) plants. In contrast, mescal is made from the cooked heart of certain agave plants, and tequila, a variety of mescal, is made all or mostly from the blue agave. There are about six varieties of maguey that are best used for the production of pulque.[1][2] The name “pulque” is derived from Nahuatl. "
more -
http://en.wikipedia.org/wiki/Pulque