But it got me wondering. Does reading from or writing to something actually change the mass of it? See, if you apply a charge to something you do actually change the mass of it by a really tiny amount, as you're adding or removing electrons from the object. This probably means that flash memory will actually get heavier as you write to it, since it stores binary ones by trapping a charge on the chip.
I'm not sure if the same principle applies to hard disks (since they operate by storing a magnetic field rather than a charge), but nonetheless it's an interesting thought