I don't have personal experience with it, but I've also heard some of the things people here are saying about 'broadcasting' schools, and that almost everyone gets their start in the business by convincing some small community/college radio station to put them on the air. One other option is The Internets. In particular, this radio station use to let pretty much anyone be a DJ:
www.eggradio.com - they went under awhile back, and then resurfaced, and don't do the guest DJ thing right now. But, something to consider.