Have you ever wondered if you're being watched?

It's a feeling that's creeping in for more travelers, as stories of hidden cameras — in hotel rooms, house rentals, cruise ships, even airplane bathrooms – continue to make headlines.

Spycams were once the stuff of international espionage, with secret agents given cameras resembling pocket watches, matchbooks – even tubes of lipstick.

Pieter Tjia, founder of Singapore tech company OMG Solutions, said that cameras have become smaller and harder to see in the past three years – often hidden in everyday objects such as calculators, diffusers, and water bottles.

But how hard is it to find these cameras? And do devices designed to locate hidden cameras really work?