Czech this out.

A Czech outfit called Bladox has developed a system called Turbo SIM that basically lets you turn any obsolete mobile phone into an Always-On sensor.

For example. You can turn your dead mobile into a car alarm. No sensors, no wires. Just plug this card in place of the dead phone's SIM, in the back of the phone. If the alarm detects tilting or other movement without being disabled, it doesn't just wake the neighbors -- it sends an SMS message to any phone number you designate.

Cool, huh?

As Worldchanging.com, which broke this story to me using the jungle telegraph of RSS points out, you can create a wide variety of inputs or outputs and, for now, the software is all licensed under the GPL.

Need more phones? Put a notice on a billboard somewhere saying you'll recycle old phones. You'll be inundated before you know it. Need more applications and application sets to play with? Bladox has dozens.

This looks like the perfect hobbyist route into the World of Always On. Think of it as an Always-On Hobbyist Toolkit.