A year ago, RadioShack filed for bankruptcy protection, and a little less than half of their retail stores were sold to a major creditor. That creditor in turn teamed up with Sprint to re-open the Shacks with mini-Sprint stores inside. Opening new stores with a buddy has apparently worked well for Sprint, and now they’re teaming up with the biggest mobile retailer in Europe to open 500 more stores in the U.S. If that sounds familiar, you’ve been paying very, very close attention to mobile retail news in the last year or so.