We’re not sure if this counts as a gadget, but we love it. The Glow Brick is a clever little cordless light made from a phosphorescent lightbulb (yes, a REAL lightbulb) embedded in a block of acrylic. It requires no electricity and can glow for up to three hours, “powered” only by light it soaks up from the sun or other artificial light sources, making it as energy-efficient and eco-friendly as it is engaging. (Warning: this is more of a nightlight than a “lamp” – i.e. it is not very bright).

$35 from Uncommon Goods