Mmm...
Not exactly sure what's going on here. YouTube is doing maintenance and suddenly the links in my prior message are not working in Safari, but they're occasionally working in Firefox.
Ah, technology.
Anyway, try these links instead:
Acoustic YouTube version: http://www.youtube.com/watch?v=b_vN0--mHug
Alternative acoustic take: http://www.youtube.com/watch?v=ZbWRfBZY-ng
Official video: http://www.youtube.com/watch?v=Iv0q3cW3x1s
