phonezoo works great. you can upload your own music to the site and make ur ringtone. or you can search the long list for any. its totaly free with no spam. it sends it to your phone in a text (mms) format.
put your own mp3s onto the phone via media card and then you can set them as ringtones. if you know much about computers, download a program through which you can edit songs, that way you can cut the song up to get a ringtone exactly where you want it.