Here's my SMS story ;-)
Brazilian mobile carriers no longer accept SMS over SMTP and only accept SMS from a very few SMS Gateways outside Brazil. So most of the SMS Gateways templates that come with Amigopod simply wont work when sending SMS to Brazilian Mobile carriers (Claro, Vivo, Tim, Nextel).
I was able to get in touch with Clickatell.com, and they were nice enough to create a separate routing profile for my account to route my SMSs to a separate upstream gateway to route my SMS' to Brazil. Only issue is that they are charging me 2 SMS credits per SMS..but at least it's working.
Then I came across mobilepronto.org, it's a Brazilian SMS gateway and they route directlly to all major Mobile carriers in Brazil. I had some minor issues configuring the custom HTTP handler but with the help of TAC we got it working.
Alex