It's time for black entrepreneurs to get really serious about growing big companies, according to the National Urban League. So the organization is setting up inner-city minority business centers designed to share the wealth, connections and expertise that can get companies growing fast. The first centers, backed by both private and public sources, will open in early 2005 in Atlanta, Cleveland and elsewhere; they'll aim at black-owned businesses that already have $250,000 in sales, as well as good high-tech ideas. "We mean this to be a lot more sophisticated than some of the small-business initiatives in the past," says Marc Morial, president of the Urban League.