There have been unofficial versions of this Question Block Light concept in existence for some time, now there's one made with the blessing of Nintendo, and therefore all the shapes and ratios and sounds are just right.
£24.99 gets you one from Firebox today, with the lamps running from a USB cable -- ideal for powering it off the umbilical cord phone charger beside the bed. The only other technical specification of note is the method of activation. Mario fans will expect to be able to turn it on with a whack, and that's exactly what happens; although you press it down instead of hitting it up.
And, being officially licensed, it even makes the correct 8-bit sound when activated.