  (Abridged) We present results from 13776 radial-velocity (RV) measurements of
1278 candidate members of the old (4 Gyr) open cluster M67 (NGC 2682). The
measurements are the results of a long-term survey that includes data from
seven telescopes with observations for some stars spanning over 40 years. For
narrow-lined stars, RVs are measured with precisions ranging from about 0.1 to
0.8 km/s. The combined stellar sample reaches from the brightest giants in the
cluster down to about 4 magnitudes below the main-sequence turnoff (V = 16.5),
covering a mass range of about 1.34 MSun to 0.76 MSun. Spatially, the sample
extends to a radius of 30 arcmin (7.4 pc in projection at a distant of 850 pc
or 6-7 core radii). We find M67 to have a mean RV of +33.64 km/s (with an
internal precision of +/- 0.03 km/s). For stars with >=3 measurements, we
derive RV membership probabilities and identify RV variables, finding 562
cluster members, 142 of which show significant RV variability. We use these
cluster members to construct a color-magnitude diagram and identify a rich
sample of stars that lie far from the standard single star isochrone, including
the well-known blue stragglers, sub-subgiants and yellow giants. These exotic
stars have a binary frequency of (at least) 80%, more than three times that
detected for stars in the remainder of the sample. We confirm that the cluster
is mass segregated, finding the binaries to be more centrally concentrated than
the single stars in our sample at the 99.8% confidence level. The blue
stragglers are centrally concentrated as compared to the solar-type
main-sequence single stars in the cluster at the 99.7% confidence level.
Accounting for both measurement precision and undetected binaries, we derive a
RV dispersion in M67 of 0.59 +0.07 -0.06 km/s, which yields a virial mass for
the cluster of 2100 +610 -550 MSun.
  WIYN Open Cluster Study. LXVII.
