USA Today – American Indian tribes have 460 gaming facilities in 28 states, but none offers online gambling—at least not yet. Nevada, New Jersey and Delaware are the only states that have legal Internet gambling, but it is spreading internationally. Worldwide, online betting generates almost $30 billion of revenue a year, with Americans spending $4 billion, according to estimates from the American Gaming Association. Some of the 240 Indian tribes in the U.S. are eager for a piece of that market. It’s unclear how much revenue online gambling will bring to U.S. tribes or states. In New Jersey, for example,…