Getting that sort of thing working is great, isn't it? Almost as satisfying as turning out a really well made piece on a machine...
I recently bought an Arduino experimenters kit from these chaps:
http://www.oomlout.co.uk/ It cost 50 quid, but it came with the all important processor board, and a whole bunch of LEDs, resistors, a servo
, motor, temp sensor, yada yada. Brilliant fun, and the programming language is still C-based, so if you can get a handle on that, you're away.
As a programmer by trade (albeit not in C), I managed to knock up a keypad-operated security system in about 1/2 day, from a standing start, using a servo to operate a yale-style lock. The only problem is, the servo won't pull the comedy lock handle far enough to actually open the door - but that's just an excuse to do more machining work