Ringtone formats

Hi All

I need to provide a basic polyphonic ringtone download WAP page, and
i'm trying to work out what formats i need to create my ringtones in
to cover the major phones - it seems that most phones will deal with
mid files, is this correct?? Is there a resource somewhere that lists
all the (major) phones and the ringtone formats they use - i've looked
around but can't see anything as yet!

cheers

alex