I'm not in a class. I was just hoping to get design pointers before I tried it. Yes, "try and see" is the next step in the process.
Based on what folks have said I will indeed use a second digital pin to switch the servo supply on and off (I may even switch the display and GPS off when the servo is on, just to make sure there's enough current - an NCP1402 is driving the whole thing).
FWIW, this is going to be a "canned" reverse geocache product. It's a single 80x36 board intended to be a "backpack" on a 2x16 LCD. It'll take battery input (2 AA, C or D cells, depending on how long you need it to keep working), a single pushbutton, a GPS module, and have a servo output intended to be used as a lock.
The controller has control over the display and GPS power, and will turn them off (the GPS module will get backup power straight from the battery so it can warm-start every time) before it puts itself to sleep. When you push the button it wakes up. It will turn on and reinitialize the display and GPS, do whatever the rules of the game are (TBD), possibly open the servo and then go back to sleep.