As a Raspberry Pi is a small computer and not just a microcontroller, there are many things that can be done very simply - and one of these is to send SMS text messages via the Internet. This has been demonstrated and documented over two parts by Lauren Orsini, who first demonstrates how to use a temperature sensor with the RPi and control it using headless mode over WiFi - and then send the sensor data as an SMS using the Twilio online service, which is easily controlled using python and the twilio API.
Although the final purpose may see somewhat frivolous, the explanations give you a framework to create your own messaging system - so visit Lauren's website to get started. And for more, we're on facebook, Google+, and twitter - so follow us for news and product updates as well.
If you're looking for a more permanent way to mount circuitry to your Raspberry Pi, check out our PiBreak - the prototyping board for the Raspberry Pi. It provides labelled breakout pins for all GPIOs, a large prototyping area with solder pads, and power rails for easy power connection:
Furthermore the PiBreak also includes mounting hardware to firmly attach it to your Raspberry Pi using a nut, bolt, and spacer - and is compatible with all revisions of both model A and B Raspberry Pi computers. For more information about our new PiBreak board, our Getting Started guide, and to order - visit the product page.