Shoppers hoping to grab an iPhone Duo in person this Friday, October 23, may walk away empty-handed. Apple told MacRumors that its stores will carry only limited walk-in supply after “extraordinary” pre-order demand. Walk-in units will be offered in the U.S., U.K., Canada, Australia, Germany and several other markets, but only at select stores in Italy. In France, China, Japan, India and a handful of other countries, buyers will have to reserve online for in-store pickup instead.