Slugging is a self-organized carpooling system in the Washington D.C. area that developed in the early 70s.
The system of slugging is quite simple. A car needing additional passengers to meet the required 3-person high occupancy vehicle (HOV) minimum pulls up to one of the known slug lines. The driver usually positions the car so that the slugs are on the passenger side. The driver either displays a sign with the destination or simply lowers the passenger window, to call out the destination, such as "Pentagon," "L'Enfant Plaza," or "14th & New York." The slugs first in line for that particular destination then hop into the car, normally confirming the destination, and off they go.
No money changes hands and an implicit rule of silence is followed, unless conversation is initiated by the driver. (thx, askedrelic)
Update: This practice is also called casual carpooling in the Bay Area. (thx, adam)
Update: Michael Sippey shares a serendipitous casual carpool story.
Tyler Cowen has updated his Ethnic Dining Guide for the Washington DC area. Even if you don't live in DC, the general remarks section is good advice to keep in mind when dining out.
The better ethnic restaurants tend to have many of their kind in a given geographic area. Single restaurant representations of a cuisine tend to disappoint. Competition increases quality and lowers prices. The presence of many restaurants of a kind in an area creates a pool of educated consumers, trained workers and chefs, and ingredient supplies - all manifestations of increasing returns to scale.
Cowen also wants against ordering ingredients-intensive dishes because of inferior American ingredients.
Avoid dishes that are "ingredients-intensive." Raw ingredients in America - vegetables, butter, bread, meats, etc. - are below world standards. Even most underdeveloped countries have better raw ingredients than we do, at least if you have a U.S. income to spend there, and often even if one doesn't. Ordering the plain steak in Latin America may be a great idea, but it is usually a mistake in Northern Virginia. Opt for dishes with sauces and complex mixes of ingredients. Go for dishes that are "composition-intensive."