Helpful iPhone tip (even though I don’t have one)

I saw this somewhere and I thought I would share as it seems very useful, yet obscure:

Helpful Tip: To quickly reset your iPhone without wiping anything off it or retethering it to iTunes, hold the volume up button, the home button, and the lock button at the same time. Keep holding it even after the "Slide to Power Off" appears, eventually it will flash totally off and then you'll get the Apple logo. Let go then.