interesting idea..
i assume by SMS you mean.. txt message (or sms as we call it in australia :p)
If your not in Aus, and looking to service Aus people I have an SMS gateway you could perhaps use to SMS Aus folks
Yes, I mean mobile text messages, thank you for pointing that out. It is called SMS here in Europe too.
I already use SMS gateway that can send messages to almost every country, australia's six providers included (Globalstar Australia Pty Ltd, Telstra, Optus Mobile, Lycamobile, Hutchison 3G Australia Pty Ltd, Vodafone), I don't know if there are any more of them in Aus (can you confirm?).