When you need to look around the room, you need a dome camera. Dome cameras are mounted on ceilings to give an almost 360-degree view. Depending on their features, they can be very inexpensive, as well.
The most basic dome camera just sits there pointed at a specific spot. It's aimable by going up to the room and moving it. This usually involves someone in another room shouting "a little to the left... a little to the right..." which obviously isn't the best way of doing things. That's why people tend to opt for more expensive dome cameras that can be remotely aimed and controlled over the internet from anywhere. One advantage of such cameras is that the smoked plastic dome usually stops people from knowing exactly where they are aimed or hearing the motors that move it. This makes people less likely to misbehave if they even see such a camera.
Dome cameras are often fitted with infrared LEDs so that they have limited night vision capabilities, and come in different sizes from smaller than a baseball to the size of a large grapefruit. Larger cameras have the benefit of larger lenses, potentially optical zoom, and this means sharper and clearer HD images. Obviously you can put an HD image sensor in a very small format but as any filmmaker will tell you a bigger lens and a bigger sensor will make for a better image.
Due to the wide variation in size and quality levels, dome cameras can be an obtrusive reminder of a security system, hung several feet from a ceiling, or a tiny hidden way to spy on people who don't realize you're even there. Dome cameras have been adapted into baby monitors, home security systems, and all sorts of special applications.
And of course... dome cameras are available at Solid Signal.