RE: Veggie Fast Food
We have a few vegetarian restaurants in Austin; two that come to mind are Mother's and West Lynn Cafe (I think they're owned by the same people, though).
Although not a vegetarian myself, I love to eat at these places because they care so much about the quality of the food.
We also have a great organic farm in south Austin, Boggy Creek Farm, that sells fresh-picked produce every Wednesday and Saturday. The owners are both vegetarians, but the farm sells organic meats, cheeses, and eggs, also (produced by other area farms). I go there often on Saturdays to stock up.
I don't know of any "fast food" veggie places, though. I think it would be a good idea, but since I'm a "market-driven" guy, it seems that someone would have done it if it's a self-sustaining concept.
It would be nice, however.