Hourglasses have come a long way and now in many shape and sizes for kids to teens to unkers. But this has to be one of the coolest hourglasses out there. Made by Mach Art, this 30-minute duration hourglass is filled with an orange colored liquid that is lighter than the clear liquid. This means that it flows very slowly. How slow? Well when your flipped the hourglass upside down, the hourglass will appear to run in a reverse direction.

[Mach Art Hourglass via Oh!Gizmo]