"Two things, thousands of ways" goes the slogan, meaning tacos and burritos with add-ins. Tacos bring a trio of soft flour tortillas or a quartet of crisp corn tortillas -- you know, the type that inevitably shatters into a nacholike mess. Better are burritos, modeled after the fat ones made famous at taquerias in San Francisco's Mission District. Plus they bring more bang for the buck. Cumin-heavy, chipotle-marinated barbacoa beef and juicy pork carnitas are the best of four meats; diced grilled chicken and steak are the other options. Since 2001, all of Chipotle's pork has derived from pigs raised in a humane, ecologically sustainable way. Those same practices currently apply to nearly 60 percent of the chicken and more than 40 percent of the beef. Amazingly sources include Meyer Natural Angus beef, Niman Ranch pork, and Bell & Evans chicken. Prices range from $5.95 to $6.35. Chipotle serves up an ethically sound burrito and, more important, a darn tasty one too.