OGG Encoder - Decoder - description from Softdepia.com:
Vorbis is a new audio format that may well be the end off your mp3 collection. This is not the feeble attempt by the RIAA or other agencies or companies to introduce a way to limit your music; on the contrary this is an absolute freedom. As consumers of mp3's we don't see the requirements to license the technology from the original developer Fraunhofer and other MPEG Consortium members. We do feel it in our wallets though with the increased cost of mp3 players both hardware and software. You see, the companies who make them must pay to use the mp3 format. With Ogg Encoder-Decoder you can convert MP3 or WAV into Ogg and decompress it back into WAV easily. It also includes its own ID tag info editor. The Ogg Vorbis format is now supported by most popular media players such as WinAMP or Sonique.
OGG Encoder - Decoder is a "Free to try" program. You can download and try it for an evaluation period.