  We devise a Monte-Carlo based, optimized filter match method to extract the
thermal Sunyaev-Zel'dovich (SZ) signature of a catalog of 116 low-redshift
X-ray clusters from the first year data release of the Wilkinson Microwave
Anisotropy Probe (WMAP). We detect an over-all amplitude for the SZ signal at
the ~ 8-sigma level, yielding a combined constraint of f_{gas}h = 0.08 +/- 0.01
(ran) +/- 0.01 (sys) on the gas mass fraction of the Intra-Cluster Medium. We
also compile X-ray estimated gas fractions from the literature for our sample,
and find that they are consistent with the SZ estimates at the 2-sigma level,
while both show an increasing trend with X-ray temperature. Nevertheless, our
SZ estimated gas fraction is 30-40% smaller than the concordance LCDM cosmic
average. We also express our observations in terms of the SZ flux-temperature
relation, and compare it with other observations, as well as numerical studies.
  Based on its spectral and spatial signature, we can also extract the
microwave point source signal of the clusters at the 3-sigma level, which puts
the average microwave luminosity (at ~ 41 GHz) of bright cluster members (M_K <
-21) at (2.4 +/- 0.8) x 10^{27} h^{-2} erg/s/Hz. Furthermore, we can constrain
the average dark matter halo concentration parameter to c_{vir}=3.4+0.6-0.9,
for clusters with T_x > 5 kev.
  Our work serves as an example for how correlation of SZ surveys with cluster
surveys in other frequencies can significantly increase our physical
understanding of the intra-cluster medium.
