OK, lets go the Cingular website (ringtone section) Click here
Now First of all, find the ringtone you want (Music Tones/Voice Tones/Sound Effects/Polyphonic) then follow the below steps.
1. Preview the ringtone, easy just click the speaker icon.
2. A new pop-up window will appears. Now, right click on this window and select "View Page Info"
3. Select the "Media" tab, and the third URL (Type = Embed) is the link to the preview file.
5. Just rename content.wma to the ringtone"s name. ... Thats it!!
P.S. make sure you mail this post to your friends.. Enjoy!