Small clusters are usually thought to behave like molecules, while the larger ones are considered to show properties of the condensed solid or liquid. A critical indication of such a behavior is the transition from single to collective excitations in the clusters. We will present recent experimental examples and discuss possible changes caused by the finite number of particles. The examples will include with decreasing excitation energies: plasmons for metal clusters, intramolecular vibrations for hydrogen bonded networks, translational motions (phonons) for weakly bound systems, and, finally, rotons for superfluid helium clusters.