  With the running B, kaon and neutrino physics experiments, flavour physics
takes centre stage within today's particle physics. We discuss the
opportunities offered by these experiments in our search for new physics beyond
the SM and discuss their complementarity to collider physics.
  We focus on rare B and kaon decays, highlighting specific observables in an
exemplary mode. We also comment on the so-called B --> pi pi and B --> K pi
puzzles. Moreover, we briefly discuss the restrictive role of long-distance
strong interactions and some new tools such as QCD factorization and SCET to
handle them.
