One of my friend, Balint found this nice verse about the Spanning Tree Protocol:

Algorhyme

       I think that I shall never see
       a graph more lovely than a tree.
       A tree whose crucial property
       is loop-free connectivity.
       A tree that must be sure to span
       so packet can reach every LAN.
       First, the root must be selected.
       By ID, it is elected.
       Least-cost paths from root are traced.
       In the tree, these paths are placed.
       A mesh is made by folks like me,
       then bridges find a spanning tree.

                        Radia Perlman