Modest little college museums? Maybe they exist somewhere, on quiet campuses across the nation, but there are also magnificent university-affiliated institutions like these. And in terms of this season’s wide-ranging exhibitions, none seem limited by geography. George O’Keeffe, queen of the Southwest, is in the Jeffersonian South (at UVA); Andy Warhol, king of New York night life, is hanging in Silicon Valley; and lots of ancient Middle Eastern objects have settled in Philadelphia.