Prowl the eighth annual Howl! Festival beginning Friday evening with a reading of Allen Ginsberg's poem that inspired the arts fest. During the rest of the weekend, the Lower East Side’s bohemian roots are celebrated around Tompkins Square Park (the city’s ’60s counterculture epicenter) with concerts, poetry readings and art shows. Obstacle courses, toddler rides and a midway with carnival booths add to the fun. All ages.