I live in Potrero, where Jocelyn Buelow reigns and tacos are hard to find. So the entire neighborhood's been abuzz about Papito, Buelow's little "organic Mexican bistro" on Connecticut, just around the corner from his Chez Maman and Chez Papa on 18th. Its cute windowfront and cheery signage appeared way back in spring, but it remained closed due to permit issues until a few weeks ago and, true to form, last night there were people waiting to sit down at one of only two dozen seats.