Remember when roller skates had eight wheels instead of a "blade" and Donna Summer's "Last Dance" was always the final song of the rink session? Then you're gonna love this exuberant homage to the brief, glorious time in American pop culture when disco reigned supreme and the skating rink was the teenage hangout on Saturday night. (Don't worry: if you don't remember this time, you'll love the film anyway.) A perfectly splendid evocation not only of the late 1970s but of a lost slice of American childhood -- a period when kids could run free on a summer's day as long as they were home before the streetlights came on -- this is the tale of Xavier Smith, aka X (the hiphopper Bow Wow, a charming screen presence) and his skating crew (a uniformly delightful gang of young actors) who are determined to snatch the championship of the annual Roller Jam Skate-Off at the Sweetwater Roller Rink from skate god Sweetness (a hilarious Wesley Jonathan). The slightly heightened sense of the absurd fuels the film's self-aware humor -- it recognizes how goofy the period was while appreciating how much we all loved it -- but never detracts from its honest soul. It makes me wonder why I ever got rid of those purple glitter laces that adorned my skates when I was 13.