Hi again Courtney!
You most certainly can use the PhotoPass while you are on vacation and decide which photos you would like to purchase when you arrive home. Once you arrive, ask one of the PhotoPass Photographers for a PhotoPass after they take your photo. Every time you stop at a PhotoPass Photographer have them add your photos to the same card. When you arrive at home, log-in to the
Disney PhotoPass Website and choose the photos you would like to purchase. If there are quite a few photos that you like, you may still order the PhotoCD at that point as well.
Many people will pre-order the PhotoPass and PhotoPass+ because of the savings. If you pre-order the PhotoCD there is a significant savings and with the PhotoPass+ guests receive a Disney PhotoCD with Stock photos of Walt Disney World Resort as well.
Another tip is to remember to as the Disney PhotoPass Photographers to use your camera to snap some family photos for you. The PhotoPass Photographers will gladly take pictures with your camera as well!
Please come back to the Disney Parks Moms Panel if you have any other questions. We love to help!
Stephanie