As April showers wane and spring becomes summer, much of Washington looks toward the shore for respite from city life. Just a few hours (and one long bridge) separate us from Ocean City, Md., home of crabs, boardwalk fries and recently-transplanted Fractured Prune donuts. Local Ocean City businessmen, unwilling to rest on these laurels, have begun stocking the ideal summertime accessory: the flask/flip flop hybrid. WUSA told us about it last night, but the shoe…