*Optional, but it relaxes the dough's gluten, allowing you to roll it into pita shapes much more easily. Also, the bit of baking powder in the Relaxer helps puff up the pitas.
Mix and knead the ingredients—by hand (10 minutes), mixer (7 minutes) , or bread machine set on the dough cycle—till it's smooth. Let the dough rest, covered, for 1 hour; it'll become quite puffy, though it may not double in bulk.
Turn the dough onto a lightly oiled work surface and divide it into 8 pieces. Roll two to four of the pieces into 6" circles (the number of pieces depends on how many rolled-out pieces at a time can fit on your baking sheet). Place the circles on a lightly greased baking sheet and allow them to rest, uncovered, for 20 minutes, while you preheat your oven to 500°F. (Keep the unrolled pieces of dough covered. Stagger the rolling so that the next batch is ready to go into the oven when the first batch comes out.)
Place the baking sheet on the lowest rack in your oven, and bake the pitas for 5 minutes; they should puff up. (If they haven't puffed up, wait a minute or so longer. If they still haven't puffed, your oven isn't hot enough; raise the heat for the next batch.) Transfer the baking sheet to your oven's middle-to-top rack and bake for an additional 1 to 2 minutes, or until the pitas have browned. Remove the pitas from the oven, wrap them in a clean dish towel (this keeps them soft), and repeat with the remaining dough. Store cooled pitas in an airtight container or plastic bag.