Desperate times call for desperate measures, and with Christmas just days away, shoppers can now resort to a mobile-tech guide that sniffs out gifts as they walk. The publishers of “Where to Wear,” a connoisseur’s directory of merchandise in every “in” store in shopping capitals around the world, have released a high-tech electronic guide for New York City that scans stores in the vicinity and reports which ones have hits on the user’s shopping list. The Where to Wear “spot guide” downloads to Palm OS PDAs or smartphones. Using built-in maps and location awareness, a user can choose one or more items from a particular shopping list, and the device will scan through thousands of store listings to show which places have the item, and where they are on the map.