I think i've seen some TCL's of that type, but i am not 100%. Anyway, it should prolly work by sending http request, since those free sms services are usually somewhere on web pages...
Ignorant and lazy people will save 30 minutes by chosing simple config file. Smart ones will save 3000 minutes of *everyone's* time by opting for complete config file.
Most SMS sites change there design, to include login's, referer checks, magic numbers (hidden form eliments embeded into a page) and genral site and form changes.
This proves hard for designers of SMS scripts.
On top of this, not all providers allow you to send to any number in the world. Thus scripts have to cope with being able to serve with many different providers.