There is another Anddev post about accessing the MMS part files.

acces_to_the_mms_part_file_content-t10433.html

I'm pretty sure I can figure things out from that post as an example. Accessing part files, and sms messages is a feature that should be included directly in the SDK; it is on other products.

I hope that people will contribute, to this thread, their understand of content providers and how to access sms and mms content in a straight forward learn-able manner.