Audacity
From WikiEducator
Audacity is Free Software that is often used to create and edit podcasts or other audio recordings. It is available for download here for Mac OS X, Microsoft Windows, and GNU/Linux.
An important use for Audacity for WikiEducators is to convert WAV and AIFF files to OGG files. Ogg is the preferred audio format in WikiEducator, although you can at the moment use MP3 files as well.