By hitting the pavement:
Los Angeles Speed Project has hastily organized what it's calling a "Run For Boston."
The "impromptu marathon" starts tomorrow at 6 a.m. at Santa Monica Pier and all runners are invited (info).
According to a statement sent to the Weekly:
From marathoners to casual joggers, runners of all ages and skill levels will come together, not as individual athletes, but as a community showing their support for the victims of Monday's events. As of now, almost 100 people have already signed up.
[Added at 11:18 p.m.]: Organizers tell us that runners can come and go as they please but that they plan to head about 7 miles north of the pier and then head back and go seven miles south before returning.