This project can be done in under 20 minutes.
You only need a camera that you want to hack (the hack is irreversible, if you break the IR filter!), screwdrivers and a TV remote! I found mine on eBay The process is really simple:
1- Open the camera so you get access to the IR filter, which is in front of the sensor. The CCD sensor is very sensitive, try not to touch it or it will be damaged.
2- Remove the IR filter: it is a red-colored piece of glass. Depending on your camera, it may be embedded in the lens (as in this example), or it may just be a small piece of glass that does not need to be broken, just take it out. If that's the case, you can just re-attach it if you want to have a "normal" camera again.
3- Put all the pieces back, and play around! You can also buy IR LED lights and make a more powerful torch (for example in http://www.ebay.com/itm/5WATT-5w-5-modes-940nm-in...
And you are done!