One year after St. Louis' food-truck scene exploded, let us acknowledge the truck that started it all: Pi on the Spot, the mobile version of the wildly popular Pi Pizzeria. Pi on the Spot's being first isn't important in and of itself. (Indeed, if you want to expand the discussion to all food trucks and not simply those riding this latest trend, it wasn't even the first.) What Pi on the Spot did, however, was establish a strategy that each of the seemingly endless parade of subsequent food trucks has followed. That strategy is based on the (correct) premise that in mobile as well as stationary real estate, the key is location, location, location. Specifically, Pi on the Spot nailed three spots rife with potential diners: downtown, the Wells Fargo campus at Market Street and Jefferson Avenue and the Barnes-Jewish campus in the Central West End. In addition, Pi on the Spot has been an outspoken proponent of Square, a new technology from Twitter co-founder (and St. Louis homeboy) Jack Dorsey that enables vendors to process credit and debit cards using smartphones — vital for food trucks in our increasingly cash-free society. Finally — crucially, but easily overlooked in the rush to praise the latest and hippest fad — Pi on the Spot has the bricks-and-mortar background to turn out a quality product again and again. Best way to triangulate on the truck is to follow it on Twitter: @PiTruckSTL.