A Layman's Guide to M-theory

The best candidate for a fundamental unified theory of all physical phenomena is no longer ten-dimensional superstring theory but rather eleven-dimensional {\it M-theory}. In the words of Fields medalist Edward Witten, ``M stands for `Magical', `Mystery' or `Membrane', according to taste''. New evidence in favor of this theory is appearing daily on the internet and represents the most exciting development in the subject since 1984 when the superstring revolution first burst on the scene. (Talk delivered at the Abdus Salam Memorial Meeting, ICTP, Trieste, November 1997.)