About 15 years ago I arranged some rocks to line the perimeter of a turn-around on our driveway. At the time, I had no idea that I was creating ideal habitat for Pixie Cup lichens. This photo shows the results of many years of slow but steady growth.
While tromping through the woods today, a fallen Alder branch blocked my path and these tiny fungi were right at eye level. The largest one is only about 1/4" long.