How to make your own iPad Pixelator
What you'll need:
One set of Hasbro's "Don't Break the Ice" +1 extra block for a total of 35
One or two rulers
A tube of clear glue
A flat working surface
(Optional) Fine sandpaper

The game comes with 34 blocks, but you will need 35 for this project. This leaves you needing to fill the gap. Maybe you'll find a 2for1 sale. Perhaps an old set in the closet. You could even organize a "group buy" with 34 other people who are making iPad Pixelators.
A word or two regarding the glue. Since this project is about light, you want to use a transparent adhesive. You may be tempted to use crazy glue, but the short working time makes it a bad choice here. Airplane cement or "Clear Liquid Nails" have great working times and dry up solid. Less is more here, you do not want glue coming out of everywhere. Be sparing. You might be tempted to apply the glue directly from the tube. This works great until anything other than normal happens. If you have no phone, pets, kids, or front door, go for it.

On a small paper plate, squeeze out a glob of glue (toothpaste shown for clarity). Using a toothpick, apply the glue in a small area in the center on one side of the first block. Remember, you don't want this squeezing out onto the table or you will have to pry the project up later!

Touch the two first blocks together and set them alongside your ruler, using it to align them.

Take your next block, apply the glue and add it to the first two.

Continue this way until you have your first row. Once the first row is done, take a moment to be sure the blocks are aligned. Don't press them together too hard, you'll squeeze out the glue! Any small gaps can be filled in later.

Begin a second row in the same way as the first. This time, apply glue on two sides so the rows are glued together.

Continue until all 35 blocks are arranged into a 7x5 grid. Use your rulers to align and square up the blocks. Once you're satisfied, allow it to dry completely.

Once the grid has dried, carefully apply glue into the small holes in between the cubes and to any gaps that look suspect. Let dry.

Lay a sheet of sandpaper flat on your worksurface, grit side up. Sand the pixelator front and back until smooth. The goal is the make the back or "open" side as flat as possible so that it sits flat on the iPad. The front can be sanded down to a smooth matte finish if desired.
Load up a video, press play and set the pixelator over the screen. There are also many apps that create colorful onscreen graphics. One of the best ones I've tried is "SpawnHD". It is highly configurable and includes the ability to respond to sound. Enjoy!

Here is a youtube video showing how it in action:
http://www.youtube.com/watch?v=um1ZjIHukFA&feature=youtube_gdataP.S. Here's a link to get the blocks directly from Hasbro:
http://www.hasbro.com/customer-service/orderform.cfm?sku=04784S500