A research group is predicting that 60 million people in the US will be listening to podcasts by 2010 - more than the total population of the UK which is just over 59 million.

The Diffusion Group expects that the increasing use of digital music players like the iPod will drive growth at 101 per cent per year for the next five years.

By the end of this year they expect that 4.5 million US citizens will be listening to podcasts.

The number of shipments of digital players in the United States is expected to reach 54.3 million in 2010 from a projected 15.5 million this year, according to the researchers.

"The average consumer only owns 1,000 songs, so from the consumer's perspective, they have all this extra storage that they're willing to fill up with adequate content. It doesn't have to be compelling," Freedman told EETimes.

The population of the US was 281 million in 2000. The UK's population is 59 million.