which gives, after 192,642 generations with the rules 01100;00010, a cycle of 72.
Florian Fischer sent us another solution with the rules 01100;00100:
In Florian's solution, you can see the Tree of Wisdom representing John Conway's immense knowledge, an aura showing his influence on us, a star at the zenith symbolizes his guidance and, at the corners, four little ornamental angels in the shape of gliders remind of his Game of Life.
It runs for 6,792,329 generations before entering the 72-length cycle.
Bertram Felgenhauer sent us the longest tail (10,069,808,235 generations): rule=01100;00010