This sample application uses Erlang and Webmachine to send SMS via Tropo.

You can start a web server and make a post request that contains phone number and the message.  This can be done via a web page that contains a post form or a commandline utility such as curl.  Note that to use this application, you need to have a free developer account available at http://www.tropo.com/

Create a Tropo script application which contains this line:
message $msg, { :to => 'tel:+' + $to, :network => 'SMS'}

Then add a messaging token to you Tropo app.  That's all you need on the Tropo front.  Now let's talk about Erlang and Webmachine.

README : this file
Makefile : simple make commands
rebar : the Rebar build tool for Erlang applications
rebar.config : configuration for Rebar
start.sh : simple startup script for running sendsms
/ebin
  /sendsms.app : the Erlang app specification
/src
  /sendsms_app.erl : base module for the Erlang application
  /sendsms_sup.erl : OTP supervisor for the application
  /sendsms_resource.erl : a simple example Webmachine resource
/priv
  /dispatch.conf : the Webmachine URL-dispatching table
  /www : a convenient place to put your static web content

You probably want to do one of a couple of things at this point:

Now proceed to the Erlang app.
0. Build the skeleton application:
   $ make
   - or -
   $ ./rebar compile

1. Start up the skeleton application:
   $ ./start.sh

2. Change the basic application:
   edit src/sendsms_resource.erl
   This file is responsible for process post request and create a get resquest for Tropo.

3. Add some new resources:
   edit src/YOUR_NEW_RESOURCE.erl
   edit priv/dispatch.conf
   For this application, I have added the following path:
   {["sendsms"], sendsms_resource, []}.

4. Run curl "http://localhost:8000/sendsms?to=1650898xxxx&msg=foobar"

This will send the message foobar to the phone number 1650898xxxx, notice you need to use the country code "1" as it is required by Tropo.