Karl Rove may not have been at Lollapalooza in Chicago this past weekend, but Crossroads Generation, the youth-aimed group associated with his American Crossroads Super PAC was. Crossroads Generation, or "XG" in teen text speak, aimed mobile ads at people in Grant Park on Friday, Saturday, and Sunday, right under the nose of staff at Obama campaign headquarters nearby. The campaign was a mere trial, but it signals bigger plans for Crossroads Generation, which wanted to test the efficacy of mobile ads targeted to concertgoers' devices using location-based data. Crossroads Generation is a joint initiative of American Crossroads, College Republican National Committee, Young Republican National Federation, and the…