Tokenism is the practice of using a member of a minority group in order to prove how "progressive" your organization is. For instance, Alan Keyes was the Republican Party's "token black" and would still be if Alan Keyes weren't too fucking crazy even for Republicans (they now have Michael Steele, Allen West and Herman Cain). Some companies will hire one representative of a given group—for instance, one black person, one gay person, or one woman—to give the entire company the appearance of being inclusive.
Similarly, traditionally exclusionary organizations such as private schools will go out of their way to put photos of minorities in their literature, creating a parallel Bizarro World of multiculturalism that does not exist in said organization's objective reality. It's why Bob Jones University has photos of black guys and Asians on the front page of its web site.