This Daft-Punk-inspired helmet I made is controlled entirely by an Arduino Duemilanove (http://vimeo.com/10684953).

It's fairly complex as far as Arduino Projects go (it involves timer interrupts, a Serial Peripheral Interface with shift registers, and a homemade PCB), but hey, I managed to do it, and I didn't have a lot of prior experience with either C or hobby electronics.

The Garduino has been garnering interest with gardeners in my city: http://garduino.dirtnail.com/

The AeroQuad is an interesting implementation.

http://diydrones.com/profiles/blogs/aeroquadan-arduinopowere...

Baker Tweet uses the Arduino - http://www.bakertweet.com/

The official Arduino blog always has lots of interesting examples too - http://arduino.cc/blog/

This guy built an awesome scooter display with voltage monitoring, temperature, GPS, speedometer --

http://www.janspace.com/b2evolution/arduino.php/2010/06/26/s...

There's also some interesting stuff if you poke around hackaday.com

I ordered a sanguino kit and learned to solder at the same time :)

If you're interested in learning the whole parts procurement process, you can also buy a PCB of pretty much any arduino-based board with no components, then pick out the components you want yourself and solder away.

For auxiliary hardware for the Arduino, use a breadboard, and get components from a salvaged electronic device - an old pre-2000s TV is best, but anything will do: a radio, stereo system. They should ideally be pretty old so that they contain enough discrete components. Newer stuff is all SoC - System on a Chip - just a big proprietary non-reusable chip and very few other components.

You can desolder and reuse pretty much any component: connectors, passive elements (resistors, capacitors), switches, active elements (diodes, transistors), LEDs, speakers, relays. You can even reuse bigger functional blocks like power supplies or power amplifiers. I used to do this all the time when I was a teenager.

Nothing like having an idea at midnight and scavenging the components to try it out at once, and not having to wait next day to buy them. Plus, it reduces e-waste, which is horrible to recycle, despite what we are told.

And stay safe, learn you electric safety rules!

PS: nice first project idea - light alarm that wakes you up in the morning, like the fancy, pretty expensive Phillips Wake-up Light Alarm devices. Later, make the light able to fade-in using maybe a thyristor. A nice enclosure is hard to make though - that's where Phillips has the advantage.

I did an Ignite talk last month about wearable computers:

http://www.vimeo.com/13163175