I lead a pretty tame life...the kind of life that doesn't leave me worried that someone's spying on me with a hidden camera.
Oh, I suppose that every now and then, a security camera at the grocery store zeros in on me to make sure I'm not stuffing mangoes in my pocket, but really, does that even count?
Just in case, however, I'm going to file away this Instructables post on how to detect a hidden camera.
It's simple, really. You just find yourself a cardboard tube (think toilet paper or paper towel) and a flashlight. Put the tube up to your eye, then turn the flashlight on and hold it at eye level. Scan the room for any points of light being reflected at you. When you find one, investigate.
Of course, they could also be harmless pieces of floating dust, reflections off glass and home decor, or anything else that bounces light back to you. That's what I found at my house when I tried it. But if your life is more exciting than mine, you might just discover that you're being watched.