My wife just got a Motorola “Cliq” phone, and wants to put her iTunes files on it. The files have to be in mp3 or .wav format. Is there a resource I can use to convert the iTunes format to mp3 or .wav?
If the files are DRM-free (unprotected, most newer iTunes store purchases), you can right-click on them in iTunes and select “Convert to MP3.”
If they’re protected AAC files, the best you can do is burn them to a music CD, then re-import them CD as MP3. Whether this is worth it to you or not depends on how many songs you want to convert. If you’ve got a lot of them, it might be easier to just buy an iPod Shuffle for the music and use the phone as a phone.
In either case, there will be some loss of quality in the re-encoding, but nothing you’re going to notice over ordinary headphones or cellphone speakers.
ETA: Many modern devices will support (unprotected) AAC as a native format, too, so you might see if you need to convert them at all.
When I right-click, even the newer files don’t have a “convert to mp3” option, but they have a “create AAC version” option. 
What a pain.
Simplest thing to do would be burn to a CD-R(or -RW) then rip them back. Kind of a time-consuming pain in the ass, but it’ll work.
A more complicated solution would be to create a virtual CD and then rip them back. I don’t know what platform you’re using, but a simple google search for “virtual CD” should yield appropriate results, or you can try Tunebite(Audials One Multimedia Recorder).
You can try Foobar, which is great and converts all sorts of formats with a click and it’s totally free
Monkey Audio’s Free version also will convert formats. There is a pay version but you don’t need it.
A lot of people perfer Monkey Audio over iTunes and it works well with an iPod
Make sure your import settings are set to MP3.