A lot of inexpensive and aged Motorola GSM handsets might not be the latest thing, however they have one very useful characteristic - their ease of interfacing with an Arduino. You can connect the serial TX/RX lines straight into the phone using a hacked headset cable and control them with normal AT commands. This has been demonstrated once more by Matthew Sheffield with a Motorola c168i. He demonstrates the required wiring and Arduino sketch to send an SMS on demand, for example:
You can also use Motorola C261s for this type of project as well, so keep an eye on eBay or the discount stores for a cheap Arduino-SMS gateway. For the details - click here. And for more, we're on twitter and Google+, so follow us for news and product updates as well.
If you find this type of project interesting, get yourself a copy of "Practical Arduino" by Jonathan Oxer and Hugh Blemings:
Create your own Arduino-based designs, gain an in-depth knowledge of the architecture of Arduino, and learn the easy-to-use Arduino language all in the context of practical projects that you can build yourself at home. Get hands-on experience using a variety of projects and recipes for everything from home automation to test equipment. For more information and to order, click here.