Easy Way: just add them to the iTunes Library via Add to Library or Import via the iTunes file menu.
I have Flip for Mac installed. Most of my MP3's in iTunes were WMP format.
OSX 10.4.7
Converting WMA Files
In iTunes for Windows, you can convert your unprotected WMA files to AAC files (or whatever file format is chosen in the Importing pane of iTunes Preferences) without changing the original WMA file. Simply drag the WMA files into your library in iTunes and iTunes does the grunt work, converting them for you. Windows Media Player 9 or later must be installed to convert unprotected WMA files. Protected WMA files cannot be converted.
There a small freeware program called "switch" that can convert WMA's to mp3's as well as other format. Its easy to use and free so I recommend looking it up.
That works only on the Windows version of iTunes. For Macs, try MP3 Converter for Mac. Of course, it's better to re-rip the tracks if possible, to ensure the best quality.
Old thread, but still very useful. I too looked for a converter for mp3
for ages and stumbled across your forum,I tried using switch today on some WMA files and it gave me an error saying that mp3 was not able to open as power pc apps are no longer supported ??
I did find the intel version of Switch. The download is not very simple to find. It's on this page: http://www.nchsoftware.com/download/index.html
the correct file name is switchmaci.zip (not switchmac.zip)