Asimov was dead wrong about the robot apocalypse -- as it turns out, our benevolent overlords at Aperture Science are pretty kind, after they've tried to kill us, at least. Valve has released Volume 2 of its Portal 2 soundtrack for free download, much like its predecessor, Volume 1.

The second installment of "Songs to Test By" contains 18 new tracks and 14 ringtones for iPhone and Android devices. New songs include "Bring Your Daughter to Work Day," "I AM NOT A MORON" and "PotatOS Lament," and you can now have the orange or blue portal sound as your messaging ringtone. Volume 3 is "coming soon" so turn up your cell phones and get ready to really impress the opposite sex with your nerd-noise machines this summer.

This article was originally published on Joystiq.

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