I think
Simon Millward
wrote a whole OpenACS package for doing SMS and used it (heavily?) in
Production, but now that he shut down his little
OpenMSG
company and their website disapeared, I'm not sure where to find it.
Oh wait! Roberto and Simon added it to OpenACS contrib back in
Dec. 2003, look in "
contrib/misc/smsc
". No docs though;
I'd track down Simon and ask him more about it...