Sarah, you have a magical land and sea trip planned.
Disney's PhotoPass+ is a wonderful way to capture all those moments without missing someone from your party who is behind the camera. I tend to be missing from so many of our family pictures because I am busy taking them, so I love that Disney has this awesome service. Since you are leaving for Walt Disney World in 10 days, you have missed the window to pre-purchas it as this has to be done no later than 14 days prior to your arrival.
Never fret, you can purchase PhotoPass+ at any of the PhotoPass sales centers in the four theme parks as well as at Team Disney in Downtown Disney. It will then be valid from 14 days of the purchase date, so you will be all set for the photographers to capture your pixie-dusted moments during your stay at the Walt Disney World Resort.
Unfortunately, PhotoPass is currently unavailable on the Disney Cruise Line.
Enjoy your dream-filled vacation and say "cheese"!
~Allison L