Portal: Terminal Velocity
You can tell this is real because only engineers have acting skills like that.
Say what you want about your asshole friends, having a portal gun sure makes changing the batteries in your smoke detectors easy...
Best Portal comment I read, from just before Portal 2 came out:
$someperson: "oh noes, Porttal 2 is coming out this weekend, but it's really nice and sunny outside"
$someotherperson: "Simple, one portal out in your garden, one in the roof above your computer, sunshine while you play!"
Strange - Facebook's preview text for the video when the link is pasted has the video description starting with "Better quality version on Vimeo.com, https://vimeo.com/43800150 My interpretation of what a real POrtal gun would be like if one existed." The current YouTube version has that removed, and the capitalization of POrtal fixed.