I have a 8700 for myself and recently bought a 7100 for my gf. Since i was easily able to load up mp3 onto the 8700, it became imperative that I get some kind of decent ringtone for my girl... But, in spite of the great info dug up by all those on the threads here, getting a ringtone onto the 7100 proved much more elusive.

The basic steps which have worked for me are as follows:
1. Convert mp3 into a wav (i used windows PCM .wav format). There are a large number of programs out there which can do that easily. I myself used Adobe Audition. One thing of note, make sure the sound is not too loud (reduced amplitude) otherwise it'll get distorted later in the various conversions.
2. Convert .wav into a .adp file. I followed the other FAQ's instructions to use Philips Mobile Tools but like others, the program failed to show any audio files at all in the file explorer. After trying in vain to find another program which would do the same, i finally came upon just the multimedia portion of the Mobile Tools, shared here at this address: "rapidshare .de/files/10817251/multimedia.zip. html" (watch for the extra space since I don't have enough posts to put up URLs yet)
This one finally worked great for me.
3. Upload to "www .coolservice . dk". There is a link for Free Uploader right at the bottom. Follow the instructions and navigate to their wap site with your 7100 and input your file's id number.
4. Download, save and enjoy!

Thanks to all on the forum for contributing. None of this info is new because of me but since it took me hours and days to piece it all together, i thought I'd post the specific instructions that worked for me in case it will help someone else. Good luck!