Tutorial: Easily Power a Mac Mini without an inverter or special power supply
Today, I finally got my Mac mini powered in my car.
I've placed a connector in the wire that lets me quickly and easily transfer my Mac mini between my car and house by unplugging the connector from the car and plugging it into the Mini's power supply.
You don't need an inverter or a special power supply... just a laptop car adapter that gives out 18v (link on the page) and a couple of other of little, easy to get bits.
I've put photos and a walkthrough on my site: http://www.kennettnet.co.uk/astramac/power/
Hope it's interesting and/or helpful to you all.