10 Insanely Cool Gadgets under $20.

Loud and cheaply packaged, but it does what it claims and is fun to play with.

A simple, responsive writing slate that is slimmer than a tablet and has a long-lasting battery.

The cheapest anti-slip mat he has come across, and it sticks things to walls without adhesive.

A clever magnetic cable organiser, though it can't handle wider cables like laptop chargers.

Interesting magnetic putty to play with, but it leaves an oily residue on the fingers.

Powerful, nicely finished magnetic balls that suit fidgeters, despite some quality control issues.

A great concept, but the flying part often lands too close to be useful and the controls feel cheap.

Eye-catching indoors and good enough as laces, though less flexible and weak outdoors.

Sceptical at first, but it genuinely reseals opened packets for very little money.

An inexpensive, good-looking diffuser that doubles as a humidifier, though oils aren't included.