Don't bother telling the Sunday regulars at John F. Kennedy Jr. Drive and Sixth Avenue in Golden Gate Park that disco's dead. Still carrying the torch for the 1970s roller-skating pastime, they're having way too much fun eight-wheeling it to hear you. (Then again it could be the boomboxes blaring "Rapper's Delight.") Like Haight-Ashbury nostalgia, but way more authentic, this tiny time capsule of sounds from Chic and Sister Sledge is still dy-no-mite. Watch the rainbow population have a blast as they do the bump, shake their groove things, finesse some fancy footwork, and even flounder, and you'll almost miss the good old days when multicolored suspenders, frizzy perms, and glittery shoelaces were considered cool.