Fruit and berries collected include forest strawberries, blackberries (lots of!), sloe, whitethorn, rose hips, and elderberry. Aside from eaten fresh, they are used to prepare juices, jams and jellies (including the typical North German / Scandinavian "Rote Grütze"). They are also used for making liqueurs. Especially sloe liqueur is very tasty - obviously not only in my opinion, because when we set out to collect them in late autumn, we typically find most bushes already harvested by somebody else. Btw, according to Wikipedia, the stomach of Ötzi, the "Iceman", contained sloe residues.
http://en.wikipedia.org/wiki/Rote_Gr%C3%BCtze
Elderberry flowers, and woodruff ("Waldmeister") are traditionally used to prepare syrup. The syrup, mixed with white wine, sparkling whine, or (sourish) Berlin white beer ("Berliner Weisse"), is a popular spring and early summer drink. Of course, you can nowadays buy woodruff syrup, since a few years also elderberry flower-flavoured sparkling whine, in every supermarket, but many people in the countryside still prepare such syrups at home.
http://en.wikipedia.org/wiki/Galium_odoratum
http://en.wikipedia.org/wiki/Berliner_Weisse
Finally, various wild herbs and berries are used in traditional medicine and for preparing teas. Many of those, including camomile, rose hips, malva, raspberry leaves, St. Johns wort (hypericum), achillea, etc. should be used across most of Europe. Marigold (calendula officinalis) lotions have traditionally been prepared at home (gently heat the flowers in some animal grease) to cure skin infections - today you of course get them in every pharmacy. The leaves are also tasty as salads.
Tea from linden (tilia) tree flowers helps to recover from a cold (note German "lindern"= to alleviate in this respect, a parallel to the salvia herb and Latin "salvare">to heal). We are collecting linden flowers wildly. Actually, "wildly" is not really correct. Ancient Germanics used to gather under linden trees to celebrate and dance, and also to hold juridical court (probably, the sequence was the other way round, first the court, then the celebration). Accordingly, village squares and main roads were (and are still) lined by linden (e.g. Berlin "Unter den Linden"). So, in fact we are collecting linden flowers on the village square (on which our house is located).
http://en.wikipedia.org/wiki/Tilia
We also used to have a good stock of juniper berries collected a few years ago during an excursion to the Luneburg Heath, but the stock has depleted now and needs replenishment. We use juniper berries to spice red cabbage and "Sauerkraut", also meat stews and game dishes (more on that in another post). There is of course a long NW European tradition to use juniper in alcohol production (Gin, Genever etc.), but so far, we ourselves have turned to supermarkets in this respect.
http://en.wikipedia.org/wiki/L%C3%BCneburg_Heath