All company-owned AT&T stores will be closing at 4:30 p.m. June 29, to prepare for the iPhone launch. The stores will then re-open at 6:00 p.m. to begin selling the device, according to a Boy Genius Report article. The report claims that iPhone shipments are expected to arrive within the 4:00 - 6:00 p.m. timeframe that day, keeping unscrupulous employees from selling the device early. The store’s iPhone display is also expected to be setup…