It would be nice if fotobuilder included the option of having the same picture in more than one gallery without actually taking up any more space.
Also I would like to see not just galleries to have different security views but also each individual picture. Also current friends filters should be allowed to be set not just private/friends/public.
Then I'm not sure if it does it or not but a "new pictures uploaded" friends page that shows the pictures either by thumbnail or placeholder that people have allowed to be viewed. Much like the current friends page in chronological order.
Those are my ideas. Please forward them to the appropriate code monkeys.