If you want wheat substitutes or gluten free:
I use millet flour for crispy crusts if I need to fry something like fish. It's very mild. Could also use cornmeal even coarse grained.
In fact my bread is a millet bread with flax and no yeast. It's really good. It looks like a light rye.
Arrowroot instead of corn starch. Or even Xanthan gum which works in hot or cold recipes. Great for thickening up a smoothie.
Spelt flour is another good substitute for wheat but is not gluten free. Rudy's spelt tortilla's come in whole grain and white. Taste like the real thing but is even better for baked goods and pastries because it's lighter due to lower gluten. It is used in pastries in Europe for this reason and gives better rise. Vita Spelt sells spaghetti, angel hair pasta, elbows, spirals and lasagne noodles in white and whole grain. I use it extensively. But there is also rice flour whole and white for those who want no gluten at all. I haven't used that much though.
http://www.molecularrecipes.com/hydr...e/xanthan-gum/
Stevia for calorie free sweetner.
I'll think of more later. I've experimented with lots of substitutes.