Our reaction: AMAZING!
So we decided to beat it, and so got a color copier:
It has lower quality, and there have been plenty of copiers and printers made out of lego and/or NXT, but ours was the first with 3 colors, 3 motors, and a color sensor. The concept is simple: There is a pointer attached to a gear rack, and the pointer pushes down markers, which after the pointer leaves, spring back up because of a gear rack. It scans once, then as it returns it prints. To make up for the markers being in different places, it moves forward or backward accordingly. There are some pictures here: http://sites.google.com/site/nxtprog/color-copier-1(sorry that I could not put the images here, I lost them a while back, and since then the device has been modified

It may not be HP quality, but the ink is dirt cheap, and I'm sure there's someone who can make it better.
Oh, and one last thing: my sister is currently improving the design and making a new program, but she's still got a long way to go.
Good luck and happy copying!