As Adam Kalsey writes in the Tropo blog post, "Announcing New lower SMS pricing" sending an SMS is a trivial matter in Tropo. His language of choice is PHP, so he shows:
<?php call('+14155551212', array('network' => 'SMS')); say('d00d, Penny SMS? '); ?>
Personally, I like seeing what I can do to merge SMS with Twitter... back in December I wrote about how to use Tropo to trigger alerts via SMS based on text in Twitter, which is a variation of an app I do actually use for Twitter monitoring. My colleague Justin Dupree also wrote a cool post about using Node.js to build a Twitter IM/SMS service.
Anyway... all of these SMS apps are now able to be deployed in production for only 1 cent per message to and from US numbers. Text messages to numbers outside the US are still the low 2 cents per message. If you'd like to try it out, Tropo is free for developers to build and try apps... you just have to sign up for an account.
P.S. In case it wasn't crystal clear, Tropo is a service of Voxeo, my employer. However, I wouldn't write about it here if I didn't think it was cool!
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