Ferrocene--the prototypical metallocene--is a fascinating molecule. Even though it was first discovered over fifty years ago, research into ferrocene-containing compounds continues apace, largely stimulated by their successful applications in catalysis, materials science and bioorganometallic chemistry. Ferrocene derivatives are now recognised as useful starting materials for the preparation of new organometallic complexes and functional materials, efficient catalyst components, as well as redox-active modifiers to biomolecules.