mobile phone: the power is not to do always a device to call someone, if not is all we can do with this invent.
washing machine: I can't iamgine me doing the washing clothes tasks every week manual way .
laptop computer: It's the same powr tahat the mobile phone, but in this case it's more confortable to work with them. Maybe, in a next future, this rason can change.
memory card: The power of data storage. It's impossible have enough space in boockcase to save the information off a memory card.
digital camera: This invent finished with the pictures in black, moving or whites.