If you've never heard of Portal, this mod will be something really new and exciting for you, and if you did you already know to expect awesome. For those unfamiliar, Portal is a game franchise developed by Valve which bases it's puzzle gameplay on shooting your portal gun to place portals that are connected. There is a pair or portals, and walking through one of them makes you exit through another. Now that you have the core concept in mind, there is a lot more stuff in the game, and therefore in this mod. Let's take a look.
The core of this mod is of course the portal gun. It's very expensive to make, but when crafted allows you to place a blue portal with a left click, and an orange one with the right click. It's equipped with all sorts of sounds from the game itself, and has a special overlay identical to the game as well. Besides making portals, it also allows zooming in with middle mouse (once again, just like the game), reseting all portals with the R key, and most amazingly, picking up blocks and entities with G. Yes, you can pick up a block of dirt, wave it around and place it elsewhere, and even pick up animals and mobs! It's crazy fun, and sure to keep you entertained. One of the new features is that you can now see through the portals, something unavailable in previous versions of the mod, and very useful now that it is.
A portal gun can also be crafted into other designs, blue for Atlas' portal gun, yellow for P-Body's portal gun (those are the characters from Portal, and the dyes match the portal colors) and combined with bacon to make the illusive bacon gun which fires a random colored portal every time.
One of the main uses for this mod is for custom maps inspired by the game and the mod. For this, the modder, iChun, included several blocks so map creators have more options. There's the portal spawners, which spawn a preset colored portal when powered by redstone, the Material Emancipation Grid, which erases all items except the portal gun, but that, and other options are configurable. You can also craft a Weighted Storage Cube, then give it a rose (right click) which turns it into a Companion Cube, a faithful companion that will never betray or let you down. That is, of course, if you do not choose to smelt in a furnace to obtain one of the many music disks with Portal music on them.
Lastly, because portal maps almost always include falling from heights, Long Fall Boots which negate fall damage were included. The mod also has several eastereggs that pay tribute to Portal, for example when you shoot a portal to the moon and the other one is on ground, the ground portal will begin sucking up blocks and entities to space.
This mod is amazing and incredibly fun, has a load of cool features, and has a bright future as more features (I'm keeping my fingers crossed for combustible lemons) and SMP support gets added. You could even say it's a triumph. It does require ModLoader, AudioMod, ModLoader MP and Forge, so it can cause many incompatibilities and in my opinion is best used on it's own without any other mods.
You can read more and download it here:
If you like it, don't forget to leave a quick message in the thread letting the creator know you like it, and maybe even donate a buck or two to help fund further development. As always, also leave any questions or feedback in the comment section below. I've started adding recipe links on the names of items, and bigger, easier to spot download links, per your suggestions, so keep it up.