Power Thing: Fashion X-cessory of the Year

Spike Lee goes almost nowhere without his X cap. ''I had to take it off my head for your magazine to shoot it,'' he says. For two years, X caps, T-shirts, and jackets have been promoting the arrival of Lee's new biopic, Malcolm X, due in late November. And the whole X-plosion hasn't hurt business at Lee's Brooklyn clothing store, Spike's Joint, or at his boutiques in Macy's, where, one Macy's buyer says, products are ''flying out of the store.'' Why does X mark the spot these days? ''It's simple, it's powerful, it's direct, it's to the point,'' explains Lee, ''and the Batman logo was really old.''