Lulu Organics makes a Hair Powder that is USDA Organic, Oregon Tilth Certified Organic and Talc free. The company creates all products using raw materials from fair trade co-op in Iowa. The packaging is vintage inspired, cornstarch-based and biodegradable and absolutely lovely too boot. There is also a travel size available for $9.50. I can't wait to try this product!
I personally use Federic Fekkai's Au Naturel Dry Shampoo. It is made without parabens, sulfates, synthetic fragrances, synthetic dyes, petro-chemicals, and phthalates. I like that it is scent free, when I tested some of the other dry shampoos at Sephora, I found the scents to be too overwhelming.
Another option is Gentle Dry Shampoo With Oat Extract (Non-Aerosol) from French company Klorane. The company is dedicated to plant research and use with non-endangered plants and with cultivation that is easy on the eco-system. This dry shampoo is formulated without parabens, sulfates, synthetic dyes, phthalates, GMO and triclosan. It received Allure's Best of Beauty Award for the category of dry shampoo.