  A brief review of the recent developments in the physics from extra
dimensions is given with a focus on the effects of Kaluza-Klein excitations in
the Standard Model sector. It is shown that the current accurate data on the
Fermi constant and on other electro-weak parameters puts a lower bound on the
scale of extra dimensions of $\sim$ 3 TeV, and thus the observation of such
dimensions lies beyond the reach of accelerators in the near future. The
correction to the anomalous magnetic moment of the muon from extra dimensions
is discussed and one finds that with the current limit on the scale of extra
dimensions from the Fermi constant, the correction to $g_{\mu}-2$ does not
compete with the potentially large contributions from the supersymmetric
electro-weak correction. The possibility of generating Kaluza-Klein excitations
associated with large radius compactifications at the LHC is discussed. It is
shown that if such excitations are indeed produced their resonance structure
will encode information on the number of compactified dimensions as well as on
the nature of the specific orbifold compactification. A brief discussion of
difficulties such as rapid proton decay that one encounters in theories with
large radius compactifications is given.
