Hollywood's take on roller-skating is usually either delightful kitsch (TV's Charlie's Angels) or a glorification of skaters to sports-god status (Rollerball). Roll Bounce straddles the two. Mr. Wow earns the right to drop the ''Lil''' from his name with a tragicomic performance as a '70s teen dealing with his mother's death that's a surprise to anyone familiar with his rapper roots. A skate-off as therapy might be a stretch, but the Solid Gold-worthy choreography makes this coming-of-age story truly groovy. The EXTRAS will turn your mood ring dark blue with joy. Nick Cannon reveals the inspirations for his Me Decade look (Jimi Hendrix, Prince), and Bill Butler, a.k.a. the Godfather of Roller Disco, teaches moves to the cast in a fast-paced making-of doc. But director Malcolm D. Lee's commentary may overstate his film's cultural influence: ''It's quite possible by the time people rent this DVD...skating will be in full effect throughout the country and perhaps the world.''