Does turning the power "off" actually save energy?

[miki]

Anyone know if hitting the power button does more than blank the screen and disable some buttons? That is, does it save any energy?

For the Sony Reader, I know it does not save any battery charge.
For Amazon's Kindle, it would appear to (since wireless and other charge-sucking capabilities are turned off).

Anyone know if the EZ Reader / Hanlin is like Sony or Amazon?

[wallcraft]

A short press of the power button just disables the keys, I would not expect this to save any extra power.

A long press turns the device off, but the resting power load is so low that this isn't normally necessary.

[Gudy]

Originally Posted by wallcraft

A short press of the power button just disables the keys, I would not expect this to save any extra power.

A long press turns the device off, but the resting power load is so low that this isn't normally necessary.

Indeed, depending on how frequently you take some time to read, switching the unit on and off may use more energy than just leaving it lying around: The boot process is bound to use up some energy (CPU activity, several screen redraws), and the sleep mode seems to be rather power-efficient. So my gut feeling is that if you switch the unit on and off a couple times per day, just leaving it on is probably the better deal, although I'd love to see someone with more hardware knowledge than me do some actual measurements.