As you will see from the wikipedia entry at http://en.wikipedia.org/wiki/Baking_powder,
baking powder in a chemical leavening agent that includes an alkaline component (typically baking soda) and an acid salt. Sometimes such a combination is used in pizza dough together with regular yeast to be sure that the dough rises if something happens to the dough that renders the yeast ineffective. Common applications are take-and-bake doughs (see typical dough formulations at http://www.pmq.com/tt2/recipe/view/id_165/title_All-Purpose-Pizza-Dough-Formulation-for-Take-and/
and at http://www.pmq.com/tt2/recipe/view/id_164/title_Thick-
ín-Buttery-Crust-Formula-For-Take-and-Bake/), and bake-to-rise doughs (see a typical dough formulation at http://www.pmq.com/tt2/recipe/view/id_156/title_Bake-to-Rise-Pizza/
). A well known chemical leavening system that includes both an alkaline component and an acid salt and that is used in the above applications (together with regular yeast) is sold under the name WRISE. One of its key features is that it is a coated (encapsulated) leavening system that kicks in only during baking. So, if for some reason the yeast doesn't perform properly (e.g., the consumer fails to handle and bake the pizza properly in the specified time period or the consumer freezes the pizza against instructions advising not to do so), the dough will still rise. WRISE is a product that is sold to professionals but you can read more about it at Reply 1 at http://www.pizzamaking.com/forum/index.php/topic,1116.msg9932/topicseen.html#msg9932.
One commercial product that you may recognize that uses both regular yeast and a chemical leavening system (a WRISE-like product) is the Jiffy pizza crust mix, which is discussed at http://www.pizzamaking.com/forum/index.php/topic,4652.msg38349/topicseen.html#msg38349.
Domino's also uses a chemical leavening system for its cracker-style crust (thin and crispy), as discussed at Reply 28 at http://www.pizzamaking.com/forum/index.php/topic,5173.msg48353.html#msg48353
and also at Reply 27 at http://www.pizzamaking.com/forum/index.php/topic,5173.msg48331.html#msg48331.
In your case, you might consider using only baking soda rather than baking powder. This is something that I have done and have written about, for example, at http://www.pizzamaking.com/forum/index.php/topic,5173.msg43956.html#msg43956.
The hydration for the doughs described in that thread is higher than for the cracker-style dough recipe that I believe you are using (the DKM recipe at http://www.pizzamaking.com/pizzainnstyle.php?
) but I see no reason why you can't modify the recipe you are using to incorporate baking soda. However, using the baking soda at around 0.35% of the flour weight, I don't think that I would use more than 1/3 to 1/2 teaspoon of baking soda for 16 ounces of flour. Baking soda at levels that are too high can impart an unpleasant flavor to the finished crust.
If you decide to modify DKM's recipe to incorporate some baking soda (or baking powder if you go that route), please report back on your results.
EDIT (3/22/13): For the updated links to the above PMQ recipes, see http://www.pmq.com/Recipe-Bank/?additionalinfo=Pizza+Dough&areaname=&searchcustomdata=