There's really no easy way to do it (that I'm aware of). The iTunes songs are a special coded file and can only be played in itunes/ipod/iphone.
The best (and only) way to do it is to convert the file to an mp3 or m4u by burning the iTunes song to a cd, and ripping it back onto the computer via itunes. It's a pain in the a**, but it's the only way I know of to do it.
I was under the impression that you could access the mp3 files on your ipod when it is plugged in via USB. I know I could with my Zune, but it required a small XP registry change. With the ipod, the files are renamed, so the process of finding the exact song you want can be quite tedious
Can I download songs from a site straight to my 8300 without syncing my 8300 as I don't have my own pc and I have been able to download some movie trailers.
Yes you can download songs directly to your phone .. it'll take a shitload of time since you'll be only running and edge connection, but it is possible if the mp3 is being hosted on the web somewhere.