a product called versawhip? versawhip 500 & 600k (sounds like models of a blender or something) are supposed to be all-soy protein and can replace gelatin and egg white qualities for meringues, marshmallows, etc.
The cheapest I've found it was still outrageously expensive, so was just wondering if anyone has tried it. It definitely couldn't be a staple, because of its price, but for special occasions/indulgences, maybe.