On the first Saturday of every August, the residents of SE Malden Street in Sellwood transform their street, sidewalks, and yards into one big fantasy: Maldenfest. Last year, they created their own Olympic Games to rival Beijing’s, and, before that, they chose a Pirates of the Caribbean theme; once, they dreamt up a very tie-dyed Maldenstock. Add props (eye patches, trophies, and, of course, beer); some classic challenges like the balloon toss; maybe a theme-determined contest of will (Walk the Plank in a backyard swimming pool); the annual Boys Against Girls relay race (which, last year, involved rolling a partner down the street in a recycling-bin “chariot” to fill a bucket with water); and voilà: an afternoon of unabashed fun.

Founded eight years ago by neighbors Keith Forman, Julie Sanford, and Angela Winter, but now planned and attended by everyone who lives on the street between SE 14th and 15th Avenues, Maldenfest is just one of hundreds of block parties thrown annually throughout Portland.

In his books Bowling Alone (2001) and Better Together (2003), Harvard political science professor Robert Putnam lamented the decades-long decline of Americans’ involvement in their communities, measured by such things as attendance at public meetings and writing letters to the editor. But Putnam found Portland to be an anomaly: an American city whose civic participation had dramatically increased since the 1970s. A key reason, he discovered, was the city’s creation of the Office of Neighborhood Associations in 1974. Today, Portland boasts ninety-five neighborhood associations.

The Maldenites’ organization isn’t that official. And Putnam didn’t include block parties in his study. But it’s not hard to see the trickle-down (and -up) connections between political participation and fun. Just as growing numbers of Portlanders have been earnestly flocking to public meetings and joining advocacy groups, they’ve also been playing together more and more: the number of block parties has jumped from 297 in 1999 to 415 in 2008.

For tips on how to throw your own block party, read our guide.