In addition to the Auto-lock and Auto-save options that you can manage under your Settings > Packing & Saving menu, you can also force Passpack to lock up and hide on command.
Should you ever hear footsteps coming down the hall and want to hide everything quickly, a boss or colleague enters the room, you need to run out of the room for a moment - just press the Lock it Up! button in the upper right hand corner of your screen. All you'll need is your Packing Key to reenter your account when you're ready.