Toilets, cows, and Germans have all been tagged by RFIDs, but according to a new study, it's footwear and fashion that top the demand for radio-enabled tracking. In a report released yesterday, ABI Research said more than three-quarters of a billion RFID tags will be used in global apparel markets in 2011, with retailers like Walmart, Macy's, and JC Penney leading the way. Item-level tracking isn't new -- in fact we saw something similar in 2006 -- but with the likes of Walmart on board, the system is expected to grow as much as 60 percent in the next three years. The study suggests inventory and security as driving factors in the adoption of RFIDs, but we've got our suspicions. And anyway, we don't want anyone to know how much we spent on that Material Girl leopard print shrug -- not even a machine.