An amazon kindle ereader in bright sunlight being stored in a bag with sunglasses. This clearly demonstrates the e-ink anti glare technology which enables the user to read the text in bright conditions, which you wouldn't be able to do with a back lit screen, as found on other devices.
It also demonstrates the portability of the device given that Amazon claim it can store up to 3500 books.
More details of Amazon's ereader can be found at:
More details of e-ink technology can be found at: