Guyton\Walker. Untitled, 2008. Stretched vinyl on billboard. Courtesy of the artists and LAXART, Los Angeles. In lieu of commercial street spam, this Culver City billboard near LAXART now hosts the art of New York-based artists Wade Guyton and Kelley Walker. After a two-year hiatus, the two resume their collaboration in a surname self-title exhibit which also includes silk-screened wall paintings inside the gallery. Official art talk from the gallery: "By appropriating a seemingly random......