I recently started using dbpoweramp, and the music converter that goes with it. It's a free program (although there are shareware add-ons for more functionality, if you prefer). It works just fine for me, and the id3 tag editing feature is neat, for someone like me who uses a certain file-trading service 🙂
<edit>doh, I forgot to mention, but it does convert kbps, and it can also convert formats, like between ogg, mp3, and wma.</edit>
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Josh