If you have an underpowered ATX powersupply lying around, this is one thing you can do with it.
This project is sadly some what badly documented. I didn't plan to upload it on Instructables but I wanted to share it anyway.
3.3V. 5V and 12V
Step 1: Making the Box
I had some plywood in the basement that wich I made a box with, it's not perfect but it's enought.
Step 2: The Guts
For those who are interested, I changed the stock fan with an Noctua 80mm because of the smooth airflow, low noise and I didn't have any computer with 80mm mounts. It's so quite that my aquarium pump sounds like a rock consert.
Other stuff I used:
Two voltmeter LEDs from eBay
A spare toggle-switch
Some fast connectors aka. bananaplugs from eBay
Hinges I hade from another project
Random screw, wood glue and paint
A 220Ohm resistor and a 3mm blue LED
Step 3: It Works!
Due to the high Power-On voltage of the Voltmeters I couldn't use the 3.3V to show it working.
I saved the Molex connectors for future use with other projects and testing of pc components.
Sorry for the short descriptions, there are many similar projects on this site so use them for more details :)