Here's what I've found so far. I'll update the list throughout the day as I hear of more places offering free pie, $3.14 pizza or other round deals.
Hungry Howie’s: With the purchase of any Howie Bread at regular menu price Tuesday and Wednesday, get a medium one-topping pizza for $3.14 with promo code PI18.
Blaze Pizza: Build your own pie for $3.14 all-day Wednesday at the company’s 245 traditional locations. Limit one per customer and in-restaurant only.
Cicis: Buy an adult buffet at regular price Wednesday and get a second adult buffet for $3.14.
Papa Murphy’s: Get a large, thin one-topping pizza for $3.14 for online orders Wednesday at participating locations. No promo code is needed.
Bojangles’: Get three Sweet Potato Pies for $3.14 Wednesday while supplies last at participating locations.
O'Charley's: Get a free slice of pie Wednesday with purchase of any dine-in entree as part of the chain’s ongoing Free Pie Wednesday promotion.
Whole Foods Market: Take $3.14 off large bakery pies Wednesday, while supplies last.
Marie Callender’s: Buy one entrée Wednesday and get a free slice of pie with a coupon available at www.mariecallenders.com. Some exclusions apply. Also join the restaurant’s e-club for a welcome offer and other discounts.
More at USA Today