equipment recommendation - What are the types of camera supports, and when to use which?

What are the types of pods and which pod is suitable for which situation?

Is there a camera holder which can be curled around the shoulders and neck?

What are the pros and cons of them all?

Answer

Just for completeness' sake, I'll add a couple of options not touched upon so far.

Chestpod -- This is a device consisting of a shoulder harness, a broad plate that rests on your chest, and an adjustable support arm with a small ball head. It's designed to help you support SLRs and long lenses (usually using the lens's tripod ring). It is not a replacement for a tripod or monopod -- it doesn't come into contact with anything more stable than the photographer's body -- but it can significantly reduce muscle strain and fatigue when working "handheld".

Rifle-stock style suports -- These are, as the name implies, rigs that look very much like a rifle or shotgun stock, with a shoulder piece, a grip with a remote shutter release, and often a forestock to allow the user a more comfortable position to support the front end of a camera with a long lens attached. These are a lot less popular now than they were in the manual focus film SLR days since you don't have handy access to all of the camera's controls while shooting. But for birding it can still be useful (used from the prone position or with an auxilliary support, such as a tree trunk or a fallen log) since it can be nearly as stable as a tripod (assuming sub-second shutter speeds) while being much faster.

Video/Cine shoulder supports -- Devices like these are designed to give you a good compromise between stability and mobility. There is usually a shoulder hook and two handles attached 30-45cm (a foot to a foot and a half) away from the body. They're great for video, but it's very difficult to access the camera's controls while using one, and since video is a fixed horizontal format, there's usually no provision for mounting the camera in a portrait orientation.

Camera stands -- Used in studios, these are tall columns on a heavy rolling base with an adjustable arm for mounting the camera. Typically, these beasts weigh more than a hundred pounds (and can be several hundred), can support cameras weighing tens of pounds comfortably, and give new meaning to the word "stable". Surprisingly, they are often more nimble than a tripod in a studio setting; raising a camera from knee level to stepladder level is usually a matter of turning one knob a few degrees, lifting the camera support arm (which is counterweighted and feather-light to operate) and retightening the knob (and barely finger-tight will do, thank you).