Fine-dining restaurants and wine bars have sommeliers -- the in-house experts and professional drinkers paid to know more than their customers about all things grape-ish. And while the character of sommeliers has changed somewhat in recent years (going from crepe-soled and tuxedoed experts on the elder vintages to young turks prouder of their cellar's boutique bottles than some dusty old Lafite), so has the job. There are now whiskey experts, Scotch specialists and, at Mezcal, Pablo, the master of tequilas. With a sommelier's expansive knowledge and the passion of a true believer, Pablo keeps tabs (and copious notes) on the bar's sixty-some varieties of tequila. He can discuss soil composition and Mexican microclimatology like the most effete wine snob, tell you which villages produce which bottles and, in some cases, which families in those villages are in charge of the distilling, bottling and labeling. Mezcal may not have the broadest or the deepest tequila and mescal list -- but it has the best tequila ambassador in Pablo.