Dredging up an old thread here, but I'll chime in. You can find zero carb tofu in the Earthie crunchie section of your grocery store. As pointed out above, tofu by itself tastes like paste and, when uncooked, has the consistency of it as well.
If you're a hot sauce fanatic, I've found that cooking up ground beef with zero carb (no sugar added) hot sauce makes great taco meat. Drain the excess fat, then cook up thin sliced zero carb tofu in the same pan, add even more hot sauce and spices and then use the tofu as the "chips" for your taco salad.
Add cheese and the allowed amount of lettuce and onions and you're set!