From satellite to podcasts, radio programming opportunities are exploding — but the fight for profits will be ferocious.

How fast is technology turning radio upside down? Ask Brian Ibbott. Last September, when the wannabe Denver deejay started playing music on the Internet, the term for what he was doing — podcasting — had been around for two weeks. These days the 35-year-old produces a half-hour show of popular songs called Coverville. Some 9,000 devotees download it three times a week to play on — what else? — their iPods. And if they tire of Coverville, they now have 3,500 other podcasts — and counting — to choose from.

For all the hullabaloo it’s generating, podcasting is not even close to being a business yet. While startups such as Odeo and The Podcast Network are providing technological support and creating a podcasting network, right now Ibbott has barely enough ads to cover expenses, and most podcasters work for free.

Maybe a few will come up with a way to make a living doing it. Maybe not. Regardless, a trend is afoot that could transform the $21 billion radio industry. Consider the basics: With no licenses, no frequencies, and no towers, ordinary people are busy creating audio programming for thousands of others. They’re bypassing an entire industry.

The digital revolution took its time getting to radio. Now it’s exploding — and the big bang goes far beyond podcasting. As radio shows are turned into digital bits, they’re being delivered many different ways, from Web to satellite to cell phones. Listeners no longer have to tune in at a certain time, and within range of a signal, to catch a show or a game. As the business goes digital, the barriers to entry — including precious airwaves — count for less and less.

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