If you buy character photos (or get them at Akershus/Cinderella's Royal Table), there's a code printed on the side of your photo. If you put that code into the PhotoPass site, you'll get all of the pics the photographer snapped during that session. We got some GREAT candids with Belle that way. When we got back to the hotel that night, we just entered in the codes.
Also, you may want to consider the PhotoPass CD if you think you'll want a lot of your pics. To buy them individually adds up FAST.
(If you're not paying for the picture - like at Ohana - I don't think they'll let you copy down the code)