  A brief review is given on the discovery and the first five decades of the
Hanbury Brown - Twiss effect and its generalized applications in high energy
nuclear and particle physics, that includes a meta-review. Interesting and
inspiring new directions are also highlighted, including for example source
imaging, lepton and photon interferometry, non-Gaussian shape analysis as well
as many other new directions. Existing models are compared to two-particle
correlation measurements and the so-called RHIC HBT puzzle is resolved.
Evidence for a (directional) Hubble flow is presented and the conclusion is
confirmed by a successful description of the pseudorapidity dependence of the
elliptic flow as measured in Au+Au collisions by the PHOBOS Collaboration.
