Just a reference for people who search "pc fan", and to try to start contributing to an invaluable forum which taught me more than I can ever repay. I just thought I'd post the correct way to wire a PC fan, as someone who has never done it may make a mistake by wiring the easiest way; that could easily result in a short circuit. The picture below is how the wires would appear under the electrical tape, as the ends must be taped. It is also important to have a mobile phone adapter or such (easy from ebay) that matches (or slightly less) the voltage of your fan. Simply cut the plug that goes into the phone off, leaving with the greater amount of cord. Here is a visual. Don't do the top one. It seems ok, but it is not safe. Do the bottom one and tape it up, there is no way for the bottom way to cause a short circuit. It requires you to split the wires into a "y" shape. Just use a stanely knife to get it started than pull them apart for a few centremeters.
I had my pc fans wired like the first one when I was using them. Each wire just has to be individually wrapped. I wouldn't be able to do it they way you suggest, my OCD would never allow it. ha