Soy Milk, Almond Milk
Locally there's a big ad campaign for Meatless Mondays. The ads say that cattle are being treated inhumanely and contribute to environmental pollution, so people should skip eating meat once a week.
The MM Web site cites the health and environmental benefits angle only. The environmental reasons cited are: carbon footprint, water usage, and dependence on fossil fuels.
There's also a hemp seed milk--an opporunity for those marijuana farmers of Mendocino County to cash in.