  We discuss the highlights of recent developments in no-scale supergravity and
flipped SU(5), especially in the context of a very light gravitino scenario
that may explain the puzzling CDF e+e+gamma+gamma+E_T,miss event. We update the
status of both subjects and discuss the impact of the latest experimental
constraints from LEP and the Tevatron. We also comment on a new form of cold
dark matter that may solve this phenomenological `problem' of light gravitino
models. [Lecture presented by D. V. Nanopoulos at the 34th International School
of Subnuclear Physics "Effective theories and fundamental interactions", Erice,
July 3-12, 1996.]
