In case anyone has an iPhone/iPod Touch/iPad, I published a new app last year on the app store that uses guitar samples that NoiseCollector generously provided on here. I did this basic app for my graduate level 3D UI course at my local university. You can play guitar chords by "strumming" it in the air, or using the new Touch & Play mode.
It basically allows you to pick power chords of your choice and strum the device to play the samples. Also can do some cool volume modulating and hammer tap samples. A mildly fun novelty and plenty of fun for playing Smoke of the Water and Iron Man for your coworkers ha ha. Hopefully I'll find time at some point to update it and make it a little more complete.
I can't express how nice it was to have quality free samples (and very complete!) to help me on this class project. (And I got an A, yay!)
Anyway, here's the links with info if anyone is curious:
Also available is iStrum Unplugged, a similar app using acoustic chord samples provided by SpeedY, another FreeSound'er!