Depending on the focal length (the mm value) the lens is wider or tighter we say. The shorter the focal length the wider the lens and the longer the focal length the tighter or more zoomed in the picture is. There is no theoretical limit to the maximum length of a lens however the tighter you go the more pornounced shakes become. However a lens cannot be wider than 0mm and looking at a very wide (or fisheye) lens is kinda strange. Very wide angle lenses distort the image greately e.g a guy walks across the shot, he moves slowely on the side but in the middle he moves very fast and is a different size etc.
This is also what causes the hitchcock effect if your familiar with it. which I cant be bothered typing about at the moment but if you want I can explain it for you, just ask.

Make Love Not War!