Itunes and mp3 player phones

Right now I have a Moto SLVR which has Itunes on it, so transfering songs is easy. I'm thinking of switching over to Verizon for their EvDO network, but would have an mp3 player phone not compatible with itunes. Is there a way to transfer songs from the itunes library to other mp3 players phones??

I imagine there must be, otherwise Cingular, SLVR and RAZR would be the only phones Mac users would buy!

I'm pretty sure that you would have to conver them to mp3 first.

As long as it's possible, but it sound like it would be a pain; having 2 copies of every song. Maybe I'll just wait for the iphone to come out. Luckily I'm on Cingular, who is the expected carrier!!