As massive Portal fans, we couldn't not let you know about this; a Portal mod for Minecraft that looks like awesome fun.
Spotted via Destructoid, the mod features test chambers, the Portal gun and much of the same gameplay mechanics that made the original game so great.
The portals themselves aren't are flashy as in the game, but the basic mechanic of being transported from one portal to the other and the retaining of momentum as you do so is there, and the modder has built a bunch of all new test chambers, too.
Buttons, companion cubes and switches are also present, and there are even hidden chambers for you to find.
You can download the mod and see more screenshots of it in action through the source link, and check out a video below: