A vending machine software firm recently implanted about four dozen of its employees with Radio-Frequency Identification (RFID) microchips that it says will allow the employees to navigate the office more conveniently. Three Square Market, based in Riverdale, Wisconsin, said it surgically implanted the chips in about 50 volunteers on Tuesday, giving the workers the ability to make purchases, unlock doors, log into computers and perform other office functions with just the wave of a hand. The firm employs 95 workers at its Wisconsin location and has more than 200 other employees stationed around the globe.