Hi Tim, Thanks for the reply!
I'm not sure about mass messaging to cell phones... It would depend on exactly what you're trying to do. Most countries/states have regulations in place that prevent mass messaging unless it's on an opt-in only basis with a clear method of unsubscribing from further communications.
I do write some custom SMS/MMS applications, and I can help you out with that if you have a list of opt-in subscribers or clients that you'd like to send a message blast out to.
For plain text SMS, there are ways to keep the costs down, but when you're looking to send images out in a mass message without the end-user initiating the session, you could be looking at some fairly steep fees from the wireless providers as well as registration fees with your state/federal telecom regulatory agencies (In the thousands of $ in monthly fees).
This is actually the exact reason that I built seeinside.mobi the way I did, with the mission of keeping costs down for all parties concerned (agents as well as buyers) as well as to limit the amount of interference from regulatory bodies while avoiding local & international legal issues.
