This concept was discovered by me when I was just doing random stuff with my Arduino..
(Note: This project is quite outdated. It has been updated with corrected grammer but anything else hasn't been touched.. Now, this project should still work but I have not tested it recently.. Also, I recommend anyone using an AVR microcontroller to check if your microcontroller can use QTouch then you should use https://github.com/jgeisler0303/QTouchADCArduino which is a much more cleaner solution.)
Step 1: Getting Started: Things You'll Need
A Copper Wire
A LED (If you use an Arduino without one on pin 13)
IR Library (Download)
This is a bare minimum project. You can even skimp on using a wire by directly touching the conductive pin.
Step 2: Setting It Up
Now, you need to put the wire in pin 11.. That's it for the hardware setup. (Again as previously mentioned you can just touch the solder of the pin on the bottom)
Install the library previously mentioned in case you don't know how to this guide should help Guide To Installing A Library
The Script: Download
Step 3: Testing
It should print out "Touched" whenever you touch the wire..