Previously to kill a hanging app on the iPhone you would just hold onto the home button for 10 seconds, and the app would die a quick non-bloody death.  With Version 3.0 of the iPhone OS /Firmware this no longer works.  The reason for this is the firmware was also written for the new iPhone 3GS which now has the ability of Voice Control which is activated by holding the home button down for 5 seconds.

So what do we do?  We could reboot the iPhone, which sucks to do.  We could smash the iPhone which also sucks in the long run, or we could use the new, but lame technique.

In order to kill the hanging app, hold the Sleep/Power button until the “Slide to Power Off” slider appears.  At this time let go of the Sleep/Power button and hold the Home button down for about 10 seconds. You will see the app bury itself in the background and you’ll be returned to the home screen.

No blood. No grass stains, and no glass to sweep up.  The iPhone lives to assist the ninja another day.