Using proc to force a reboot

So we just had this little discussion on IRC and I figured I'd save it for posterity here:

[11:37:36]  to force a 'hard' reboot (if reboot is not working) - equivalent to pulling the power cable:
[11:37:44]  echo 1 > /proc/sys/kernel/sysrq; echo b > /proc/sysrq-trigger
[11:40:45]  come on dom, you know you want to try it.
[11:41:21]  heh
[11:42:29]  what's this do?  what's this do?  what's it do???
[11:43:13]  you tell us
[11:47:09]  yeah, that's awesome
[11:47:24]  it just tells BIOS to reboot
[11:47:35]  (or something like that anyhow)
[11:47:58]  so, immediate reboot in other words?
[11:47:58]  system just goes *blip* and starts posting

So there you go. Want to reboot without waiting for all those nasty processes to finish or phyiscally pressing the power button? That's your way out.

Thanks, toddz :D

- Arch