I've been wondering this myself. I have a ton of ringtones on my storm and was hoping the droid was "unlocked" like other moto dumbphones have been. Its nice knowing who's calling or if I'm getting an sms or mms, but I don't wanna spend a bunch of money getting all new ringtones for this reason.
I would love to have an app to set different tones for different message types. Not sure if you can save them from mms but I can save them from emails. Crackberry has a few free ones that they send as an email.
you are able to save mms ringtones to your droid. Long press on the item save to sd card. Manually connect to sd card from your computer or use Astro file manager to move the item from the Download directory to your ringtone directory and your set.