Podcast a New word, from the OED (Oxford English Dictionary)

Notes on OED's December 2008 release of new words
http://dictionary.oed.com/news/updates/newwords0812.html

podcasting n.

A very new word, for a recent phenomenon, and a great example of how technological change, especially that relating to the Internet and the media, can be a driving force not only in generating new words, but in determining whether they survive and succeed. In this case the rapid adoption of podcasting (the technology) as a means of making audio material available has seen podcasting (the word) move quickly from its first tentative steps in 2004, as only one of a number of suggested names for the process, to near-ubiquity in 2008. The current OED quarterly release also includes other members of the same family: podcast as a noun and a verb, podcaster, and even the somewhat ungainly adjective podcasted.

more from the OED:

podcasting, n.

The use of the Internet to make available digital recordings of broadcasts for downloading to a computer or personal audio player.

2004 Guardian 12 Feb. (Life section) 28/1 MP3 players, like Apple's iPod, in many pockets, audio production software cheap or free, and weblogging an established part of the internet; all the ingredients are there for a new boom in amateur radio. But what to call it? Audioblogging? Podcasting? GuerillaMedia? 2005 R. MATHIESON Branding Unbound vii. 182 Newer phenomena, like ‘podcasting’, are opening up whole new possibilities. 2008 State (Columbia, S. Carolina) (Nexis) 28 Apr. B5 The district's first class on podcasting was last year, and some schools are in early stages of launching blogging.

COMPOUNDS
General attrib.
2004 Seattle Times 18 Oct. C1/5 Geeks are going nuts over this, holding ‘podcasting parties’ and exchanging all sorts of content. 2006 Technol. Horizons in Educ. Jrnl. 1 Advanced blogging and podcasting experiences to keep up with the digital generation. 2008 Canberra Times (Nexis) 7 Jan., An example of the policy issues is the need to relax firewall security to enable the implementation of a Podcasting tool.