What is the best way to circumvent iTunes for my iPhone?

I use linux at home and I have only bought a few things off of iTunes. What is the best app that will allow me to circumvent iTunes and put my music on my phone? I've tried Oplayer free, is this currenly the best app? Is it worth upgrading to the paid version? I'm thinking I will set up a ftp server on my linux box and use Oplayer to download my music to my phone but am wondering if there's a better solution.

You should have asked this question BEFORE you chose to BUY your un-identified iPhone. We really need the Model Number, and iOS Version.

As you know, iTunes does NOT run on Linux, but there are some interesting Linux alternatives (circa 2008):

The only question is: Will the Linux Apps listed below, be able to deal with your iPhone's newer version of the iOS Operating System?