Simple idea: If you toggle this function on, Screen locking becomes active only after some delay. After waking the phone and unlocking the screen, for the next xx-minutes, repeated switching from sleep to awake does not require de extra screen unlock step. Handy when using apps that don't have 'overrule screen switch off', Handy for those who keep pressing the wrong button, Handy for those who use the G1 in a protective cradle shielding the touchscreen while using compass/GPS/bubble etc. etc. etc..