The audio module allows users with proper permissions to upload audio files into drupal. Each audio item is created as its own individual audio node.
The audio module uses the getID3 library to read and write ID3 meta-tag information to and from the audio file. Pages that display the most recent audio files submitted to the site, as well as the most recent audio files uploaded by individual users are also generated. Feeds from these pages are 'podcast friendly'.
The module also comes with the handy XSPF Flash player that is (by default) embedded in your site.
5.x-1.x versions require that you install the Views module.
6.x-1.x versions require that you install the getID3(), Token, and Views 2 modules. Some of the included sub-modules depend on the CCK module.
Note that the 6.x update is incomplete for details on what works right now and what needs testing please review the release notes.
If you don't need to write ID3 tags then you might want to look at using the FileField module to store the files and SWF Tools module to display a flash player. It takes a bit of time to get it setup but it's a much simpler result.