I've been saying for two years now that hardware is the future of software, and one center of action is the world of Arduino programmable microcontrollers. You can't really learn what's possible in a new technology field without trying it out for yourself, so I took the plunge and tried my own project, a very simple one to measure temperature and humidity in my house. Here's what I did:
I bought the following items (at Amazon)
- Arduino Uno R3 $21.95
- this temperature/humidity sensor:
Virtuabotix DHT11 Digital Temperature/Humidity Sensor $5.60. - and a $22 collection of assorted useful parts from Seeedstudio called Arduino Sidekick Basic Kit (Version 2) that includes:
Breadboard, Jumper wires, Color Led, Resistors, Buzzer, etc., all of this comes in its own handy box for easy transportation and minimal clutter. Parts list: Breadboard X1, Breadboard jumper wire X 70, Red Led X 10, Green Led X 10, RGB led X 1, Ceramic Capacitor (10nF X 10,100nF X 10), Electrolytic Capacitor (100uF X 5), Resistor (330X10,1kX10,10kX10), Tilt switch X 1, Thermistor X 1, Photo resistor X 1, Diode X 1, Buzzer X 1, Push button X 5, switch X 5, Mini Servo X 1, Potentiometer with knob X 1, Resistor Instructor card X 1, Plastic Box X 1
I installed the Arduino development environment on my Win7 PC and then hooked up this simple temperature sensor project: 
The temperature sensor is a DHT11 and Virtuabotix has easy-to-understand libraries and other installation instructions.
Here's a screen shot of the sensor and development environment in action:
The entire project took about 90 minutes, including unwrapping the Arduino UNO, installing all software and libraries, and configuring and connecting the sensor.
It's extremely exciting to think about (1) how easy it was, and (2) all the other things I'm able to try now that I have this basic level of knowledge.