At the very tail end of its Galaxy S III event, Samsung promised one more surprise -- and what it gave us was a special retail strategy. The company will be opening Mobile Pin locations, or glass-housed pop-up stores, to help showcase its new flagship phone. We had a chance to look at examples of the stores first-hand. Those not at the launch event will get a look in the near future, with Mobile Pins appearing at several locations throughout London. The first Pins will open on May 29th, with the Pin 5 (a 5-by-5 meter indoor location) making temporary appearances at Spitalfields Market, Westfield and White City, while the 7-by-7 outdoor version (Pin 7) will pop up in the Olympic Park along with Hyde Park at a later date this year. Samsung is also planning to introduce the Pin concept abroad, with plans for two US cities currently in the works, along with a yet-unnamed country in Asia -- Korea would be our guess. We've got a gallery and video walkthrough below to explore the locations in more detail.