I know this to be rather futile problem yet I simply had to ask. Ere posting here I, of course, searched the Net and took a decent look into my dictionaries, needless to say that there wasn't any consensus between them.

To winnow down the meanings of these words I picked few sentences showing precisly sense of the word(I wanted to know about):
„They walked among the deckchairs…“
„I saw a few familiar faces among the crowd.“
„Talk about it among yourselves.“
„Rescue teams searched among the wreckage for survivors.“
„They kept on amidst the storm.“
„He persevered amidst many difficulties.“
„He was sinking amidst the waves.“

Let me know if you have any idea about this matter. (when can I replace amid with among and vice-versa)

PS: Every dictionary tends to bear its own ‚true‘. One says amid is only used in meanings ‚in the middle of‘ whereas the other one indicates total interchangeability. I'm just wondering what OED states about it.

Jde o to, že AMONG/AMONGST má více významů, a synonymum s AMID/AMIDST je to jen někdy v některých významech.
1) positioned inside a group – AMONG, AMONGST, AMID, AMIDST – synonyma
(There was a black sheep among/amid/amon­gst/amidst the white ones.
2) selected from a group – tady to synonyma nejsou
(She is the best among my students – ale NE AMID!!!)
3) to each individual in a group – také to synonyma nejsou
(I distributed the photocopies among my students – ale NE AMID!!!)
4) collective action – tady to také nejsou synonyma
(There were complaints among my colleagues – ale NE AMID!!!)

I am most grateful to you for your point of view. To make your list almost complete(or rather as complete as humanly possible) I add some more general definitions. Supposing we have the meaning ‚surrounded or encompassed by‘, so for further differentiation between amongst and amidst I dare to add this:

1.Amid and amidst are commonly used when the idea of separate or distinguishable objects is not prominent.

2.Among and amongst denote a mingling or intermixing with distinct or separable objects.

i.e. He seraph Abdiel, faithful found; Among the faithless faithful only he. From amidst them forth he passed…