Minecraft and the creativity that people put towards it never ceases to amaze me. Here we have video of a mod for the game which adds elements from Portal into the game, including the Aperture Science Handheld Portal Generator, heel springs, energy pellets and, of course, test chambers.
The PortalCraft mod, in two parts, looks spectacular and the only thing stopping me from playing it right now is my burning desire to encourage you to check it out. My work here is done. If you'll excuse me, I have science to do.
Extreme PortalCraft Final Release [Minecraft Forums, thanks Smiley!]