Finally I got around to changing the ringtone on my Windows Mobile device. A quick search on how to use a MP3 as ringtone only turned up ads for applications that would do that for you. As I suspected you don’t need any special software for this – it’s actually embarrassingly easy:
Use the file explorer and navigate to the file you want to use. Tap and hold on it to the context menu appears and select “Set as Ringtone” :-)
Note: This will copy the file to the Windows\Rings folder (i.e. using internal RAM). This is a good idea because there is a gotcha:
the storage card will usually power down, meaning that if you put it on the card it may take quite a while before the ringtone is heard when someone calls you!