I'm a big fan of Inkscape, a vector art program for pretty much any OS with GTK. Recently, I started making some extensions for Inkscape. Check them out, yo!

General Installation

Most of the time, you can just drop the .inx and .py files into either the user extensions directory at ~/.inkscape/extensions or the system extensions directory at /usr/share/inkscape/extensions (may vary per distro). However, if you put them in ~/.inkscape/extensions, you'll need to copy or link the dependencies into there as well. You'll need at least inkex.py, which can be found in /usr/share/inkscape/extensions.

Pixelize

This one takes an imported bitmap image and converts each pixel into a 1x1 rectangle and adds all those rectangles to a group. Once installed, it can be found at Effects > Images > Pixelize. (Note: in the screenshot, the per-pixel outline was added to show what's going on; the effect doesn't do that.)

Update: Apparently there's a drastically easier way to do this involving the clone tool. I never bothered to learn what the clone tool did, so there ya go.

• Attach:image_pixelize.inx
• Attach:image_pixelize.py