FWIW, I found a directory structure for your SD card that should be even more useful?
After plugging in your Droid to your PC, then use the notification pull down to mount your SD card on the Droid. Then, make these directories:
There's more, but at least the above will allow you to use custom ringers and more important, Notifications (i.e. new mail/texts/MMS, etc.) alerts over and above the stock ones on the phone.