  We state and prove a general summation identity. The identity is then applied
to derive various summation formulas involving the generalized harmonic numbers
and related quantities. Interesting results, mostly new, are obtained for both
finite and infinite sums. The high points of this paper are perhaps the
discovery of several previously unknown infinite summation results involving
{\em non-linear} generalized harmonic number terms and the derivation of
interesting alternating summation formulas involving these numbers
