Martin Luther King Jr. Day has been a national day of service since 1994 — “a day on, not a day off,” so the saying goes — but many of you may be curious as to how and where you can sign up to volunteer. Fortunately, Serve D.C., the District’s official agency coordinating volunteerism around the city, has several options available.

The Obama family showed up at So Others Might Eat’s soup kitchen on Monday, as part of their contribution to the MLK Day of Service. The Washington Times provides a little color:”We got a lot of struggle in this neighborhood,” a man shouted to Mr. Obama as he entered the facility, in a hardscrabble section of the city just north of Capitol Hill. Inside, the president, wearing an apron and khaki baseball cap, handed…