I only know of one that lets you create your own spoken ringtone. It is at speechtones.com. I have done some programming work for them so I have had a chance to play with some ringones that I got from them.
It lets you pick a "Pre-Tone" so that you can actually hear it, then type "Pick up your damn phone!" and it will create your ringtone that way and then send it to your phone, or you can download it to your PC and cable it over.
It's pretty fun.

what is a good part of a song to make a ring tone

That is personal preferance.
Most tones are made using the intro, chorus or the hook.

hey,

I was wondering if anyone knew a site that would tell you what is a good part of a song to make a ring tone. I have no problems making my own but sometimes i would like some help on what part would make a good ring tone. Sometimes it takes me hours to figure out what i want, when someone out there has prob already figured this out. please let me know if anyone knows of anything like what i am talking about. thanks for your help