LAYZOR!!! is a laser light show projector made with scrounged parts and designs and software from the Web.

The theory behind this is to use a USB Sound card like http://dx.com/p/trust-5-1-surround-usb-2-0-external-sound-card-25620 or http://dx.com/p/c-media-cm106-usb-2-0-external-sound-card-box-with-7-1-speaker-spdif-optical-output-15746 as a DAC to generate signals to a set of galvanometers, which deflect a laser signal in X & Y to draw animations on a screen.

The software I'm using is called OpenLase, by Héctor Martín Cantero (a/k/a marcan). He describes it on his blog.