You can create your own ringtones using existing software: Windows Media Player, Windows Movie Maker, and Roxio Media Manager.
1. Rip your song using Windows Media Player, but under More Options, select Windows Media Audio Lossless (uncompressed).
2. Use Windows Movie Maker to edit the song, then save the file as a high quality audio wma file.
3. Use the Roxio Media Manager to import the song onto your Blackberry.