Whoa! So I popped the sim inot an old Nokia, fired off an SMS. No prob. Thought, I'd try to send a pic to myself on the Nokia. Hey! It worked on both sides!
Pop the sim back into the iPhone expecting to wait til tomorrow...but I'm impatient and so I tried it.
I can tether, my visual VM works and now, I have MMS...
This is all thanks to the nerds, hackers, impatient SOB's and entitled mofo's that make this forum so great!! I'm glad to be a part of this group. lol
Try rebooting and see if it's still working for you.