Medicinal & edible lichens

Something I am making an effort towards is that of getting to know all the different lichens in the area.

I have enjoyed rock tripe before, used it as broth, and also tried some greenshield lichen tentatively for medicinal properties. I've also made a lichen watercolor pigment a long time ago out of a lichen I call the "starry night" lichen because of their coloration and dots (they share habitat with common greenshield), but I don't know their name yet.

Do you have any experience with eating lichens or using them for medicine?

I sometimes nibble on old man's beard Usneas that fall out of the tall Fir trees during windstorms.  
I have also made simple tinctures with them.   I find it a strange sour-sweet-bitter-astringent flavor.  It is very 'medicinal' tasting unlike a more casual herbal 'chaw' such as Plantain or Sage leafs.  I don't chew on It as often, but I aim to get to know It better.
And now I'm curious to learn more about lichens as food and medicine!

*Also, always please be sure of plant identification and safe uses before ingesting... of course.*