May Day baskets filled with flowers. Really they were just paper cones that we filled with flowers from our yard and hung a little paper handle on them. We usually used Elmer's Glue but in a pinch we'd use a staple to hold them together. Then we'd stealthily sneak around the neighborhood and hang the baskets on doorknobs and wait...
We'd watch to see what would happen when people opened their doors and found a basket of flowers hanging on their door.
It was fun and no one ever seemed to mind finding flowers on their doorstep...but I wondered where that tradition came from.
So, I looked on Wikipedia:
"The earliest May Day celebrations appeared in pre-Christian times, with the festival of Flora, the Roman goddess of flowers, and the Walpurgis Night celebrations of the Germanic countries."
It's a shame that we are losing this tradition today.