spragl parent
From the comments, it looks like eating stinging nettles is quite common throughout Europe. It is definitely well-known in Denmark, and used in a number of recipes. You can buy dried and chopped stinging nettles, but they are best when you pick them fresh. The classic Danish recipe is "brændenældesuppe" (stinging nettle soup). I dont think it is as common as it used to be, as our food culture has been so americanized.
They're best when picked fresh and young, i.e. easiest to collect in spring, it's kind of spinachy but with more texture. A bechamel base from butter, flour and broth or cream is all that's needed to make a good soup from chopped nettles.