While all four major U.S. carriers have announced upcoming availability of Samsung’s flagship Galaxy S III smartphone, only two have given a solid release date. T-Mobile and Sprint both announced that the handset will be available starting June 21st, while AT&T and Verizon have remained tight-lipped regarding a potential release date. According to Droid Matters, however, after preordering the device from AT&T, the company states that orders are scheduled to begin shipping on June 18th. At the same time, Droid-Life also reports that Verizon’s orders will ship by July 9th. According to one of our readers, however, Best Buy expects Verizon’s Galaxy S III to ship by June 28th, and an image of the Best Buy receipt mentioning that date can be viewed after the break.