Is this possible ??
Have you tried saving the mp3 files in your phone's Ringtones folder?
Generally if you have a droid, and you have an app that you created the ringtones through which is something I do as well, they usually are saved to your micro sd card if you have one in your device currently.
I realize that, but more and more phones, such as the Droid Mini, don't have memory card slots. In that case, the mp3 for ringtones should be copied to the phone's Ringtones folder (or the Alarms or Notifications folder, depending on how you want to use it).
In that case yeah, I'll go through hook my phone up to my computer and drag files to the folder I need to.