Get on the (proverbial) bus for this Mexican-style progressive dinner for 10 through Presidio Heights. The evening will begin at the home of Emily and Roth Martin, where you will warm up with margaritas and a tequila tasting. Walk (or stagger) a few blocks west for a sumptuous dinner of haute Mexican cuisine hosted by Julia and Kevin Hartz.  End the evening down the street with an extravaganza of dancing and chocolate at the home of David Brailer and Matthew Rhoa, with music spun by the one and only DJ Lally.