Get Best offers of Pen Camera, Clock Camera, Watch Camera and more. With Todays Technology hidden cameras have become smaller and can now be installed in daily objects. The camera is usually hidden or disguised to stop any unwanted attention to the user. Hidden cameras have become popular for household surveillance, and can be built into common household objects such as smoke detectors, clock radios, motion detectors, pen and more. Hidden cameras may also be used commercially or industrially as security cameras.