Zeep Mobile - Cool SMS gateway, that's free!  Recently I had to build a web app that utilized SMS messages to cell phones .. The client was on a shoestring budget and needed an a gateway that wasn't going to cost anything to get up and running.  Luckily, he found ZeepMobile.

It's a really cool system, and simple API if you understand how to use cURL in PHP.  Setup is a snap .. You enter a unique name for your app, which is used for mobile users to send messages to your server end point, and then you get your API key and secret code.  Oh, you also setup your mobile urls for (more...)