those who say they are just data, what do you think humans are made of? we are all just made of atoms and atoms are made of energy and data is made of energy too. I remember the third season of digimon was all about the "ghost in the machine" theory. I remember thinking about his deeply in philosophy class last semester.
If you loose your pokewalker there is a way to recover your pokemon by holding Up, select, and the R button in the "connect to pokewalker" menu (page 52 in the handbook)