So, you may ask yourself: what can I do to get this neat-o 3d-monitor-technique? First of all: you need a monitor. I've only tried this out on TFTs; while CRTs and other displaying techniques may work, I can't guarantee anything. Be sure to take something with a lot of pixels per inch, though: for example, the video on the previous page is made on my laptop which has a nice dense 1440x1050 pixels on a 14" screen.
Secondly, you'll need a bunch of transparency sheets, plus a printer to print on them. 2 sheets should be enough, but you may need more if your first try somehow fails. Make sure the sheets are meant for your printer: inkjet-sheets in a laserprinter, for example, can melt and result in a broken printer. You'll need to print a parralax barrier that's exactly fine-tuned to your monitor. That's not easy to do manually, and that's why I created this nifty wizard to make pixel-perfect parralax barriers while wasting not more than one sheet. Follow that and you should have a precision-made parallax barrier in no-time.
Thirdly, you'll need something to create a bit of distance between your newly-created parralax barrier and the monitor. In my experience, you generally want something like 10mm of distance between the transparency sheet and the plane of your TFT, although more or less works too. The easiest way to do that is to take a piece of lexan or glass or something and tape it to the bezel of the monitor. Then, tape the transparency sheet to the lexan, with the lines as vertical as possible. This calibration-image may help you with that.
Now, all you need is some 3d-imagery to look at. I've made the little script I use into a web-based wizard-like every can use to transform a series of images into a 3d-image capable of being looked at through the parrallax barrier. The images that were generated with it (and made public) can be viewed through the gallery-page. Ofcourse, you can make your own images too: shoot 8 pictures of the object you want to 3d-ize, each with the camera focussed on the same point but with the camera itself moved to the right a bit with each step. Resize the images so they're each smaller than 1MByte or so, then upload them to the 3d image wizard.