Realizing the potential and current draw of the Internet radio market, ESPN is wasting no time staking its claim. The company announced yesterday that it is creating online radio sites for five markets including New York, Chicago, Pittsburgh, Dallas and Los Angeles. Not surprisingly, probably the five most sports-crazed markets nationally, although I'm sure Boston and Indy would have something to say about that. Regardless, it is a shrewd move on the part of ESPN. The local sites will feature a combination of national and market-specific content. The planned features include podcasts, interactive calendars, and polling systems. Perhaps it was the number of young people in one of their core targets that made ESPN act. According to our latest research about one in four (22%) of teen and college aged men streamed online radio at least once in the past month. Among those who regularly listen to online radio, more than half, (56%) say they stream sports-related content.