Something I'd like to add to the OP concerning flashing. This is an alternative method to get MMS working on your Droid. It involves modifying a file on your computer, then adb pushing it to your phone. This'll cut out the need to modify APNs manually on the phone as this file, once pushed, does just that.
Files/programs needed:
Telephony.db (
DOWNLOAD HERE)
SQ Database Browser (download
HERE)
1. Open the program sqlitebrowser
2. Navigate to, and open Telephony.db from wherever you downloaded it.
3. Click on browse data tab
4. In the dropdown box below, select 'carriers'
5. Scroll to the right, you should see in the mmsc box "http://mms..." double click
6. At the end of that line, you'll see an incomplete MDN--enter in your MDN
7. Save, close, then COPY-PASTE that newly modified Telephony.db file over to c:/*SDK folder*/tools for pushing to the phone.
8. Push to phone with this command:
adb push telephony.db /data/data/com.android.providers.telephony/databases/telephony.db
Of course, this'll be done through the computer, and decided to post it up because this is another step that doesn't necessarily have to be done through the phone. Some things are done faster through the phone, some things are done faster on the computer.