  We present spectroscopy of binary quasar candidates selected from Data
Release 4 of the Sloan Digital Sky Survey (SDSS DR4) using Kernel Density
Estimation (KDE). We present 27 new sets of observations, 10 of which are
binary quasars, roughly doubling the number of known $g < 21$ binaries with
component separations of 3 to 6". Only 3 of 49 spectroscopically identified
objects are non-quasars, confirming that the quasar selection efficiency of the
KDE technique is $\sim95$%. Several of our observed binaries are
wide-separation lens candidates that merit additional higher-resolution
observations. One interesting pair may be an M star binary, or an M star-binary
quasar superposition. Our candidates are initially selected by UV-excess ($u-g
< 1$), but are otherwise selected irrespective of the relative colors of the
quasar pair, and we thus use them to suggest optimal color similarity and
photometric redshift approaches for targeting binary quasars, or projected
quasar pairs. From a sample that is complete on proper scales of $23.7 <
R_{prop} < 29.7\kpch$, we determine the projected quasar correlation function
to be $W_p=24.0 \pm^{16.9}_{10.8}$, which is $2\sigma$ lower than recent
estimates. We argue that our low $W_p$ estimates may indicate redshift
evolution in the quasar correlation function from $z\sim1.9$ to $z\sim1.4$ on
scales of $R_{prop} \sim25\kpch$. The size of this evolution broadly tracks
quasar clustering on larger scales, consistent with merger-driven models of
quasar origin. Although our sample alone is insufficient to detect evolution in
quasar clustering on small scales, an $i$-selected DR6 KDE quasar catalog,
which will contain several hundred $z \leqsim 5$ binary quasars, could easily
constrain any clustering evolution at $R_{prop} \sim25\kpch$.
