I used wild grapes in a mead once. They were tiny little blue-black grapes. Mostly seeds inside with very little flesh. They provided a certain smoky flavor and a little astringency. Turned out pretty good.
I have also made a traditional gruit ale. Not strange ingredients, historically speaking, but consider the fact that most people have never tasted a gruit ale in their lives, ever. Tasted sort of like A1 steak sauce and pickle juice. I loved it. Need to brew that one again.
Also made an ancient Sumerian recipe with homemade bappir bread, Bamburg smoked malt, dates, honey, and wild yeast. Tasted like sour fruity bacon. Very different.
I've also used Earl Grey tea. Never again. I hated it. Tasted like Earl Grey, yes, but... not meant for beer.