It's the existential urban dilemma: train or tipple? With the S.F. Hash House Harriers, you can do both -- simultaneously. Essentially a runners' club for extroverts, SFH3 is one branch of a huge society, started in 1938 by British expats and spread to over 1,500 "hashes" around the world. The local version meets Monday nights at 6:15 -- call the hot line for the location -- gathering 60 to 80 people of all ages for a run of about five miles. The trail is marked with chalk by two "hares," who get a 10-minute head start; the quickest runners (or FRBs, for "Front-Running Bastards") call out the trail for the rest, who follow in clumps according to speed. The run ends -- where else? -- at a keg, at which, says Justin "Gloryhole" Powell, SFH3's grand master, "someone takes the mick out of everybody." As Jen "Stickypants" Peaslee, grand mattress, explains, "It's a good way to get to know the city ... and it brings you out of your shell." Plus, after a workout gets your blood pumping, a beer is more, shall we say, effective.