At South By Southwest, it’s the bands that get the hype. But there are aspects of the conference that, if you dig deeper, prove just as rewarding, if not more. One great, somewhat under-publicized facet of SXSW is Flatstock – an exhibition organized by the American Poster Institute where designers of concert posters display and sell their work. Flatstock proves dizzying: the sheer talent involved rivals that of the bands on the posters themselves. Set up in SXSW’s main conference hall, it features row after row of booths set up by the artists themselves, selling their work (often in fine-art print quality) and of course, advertising their services to the bands that are there anyway as a captive audience. The posters span everything from incredibly surreal, biomorphic images for Dead Weather to witty pop-art takes on Lady Gaga and Willie Nelson. Indeed, for all of SXSW’s web-savvy “interactivity,” it’s the gloriously old-school paper and ink of Flatstock that provided some of the week’s greatest artistic thrills, as you’ll see here…