Table of contents : Introduction.- Separation of Elastic and Inertial Properties in a Three-dimensional System.- Normal Contact Problem with a Rotationally Symmetric Body without Adhesion.- Normal Contact with Adhesion.- Tangential Contact.- Rolling Contact.- Contact with Elastomers.- Heat Transfer and Heat Generation.- Adhesion with Elastomers.- Normal Contact Between Rough Surfaces.- Frictional Force.- Frictional Damping.- Coupling to a Macroscopic Dynamic.- Acoustic Emission in Rolling Contacts.- Coupling to the Micro-scales.- What More?