  We present high angular resolution observations with the Keck Interferometer,
high dispersion spectroscopic observations with Keck/NIRSPEC, and near-IR
photometric observations from PAIRITEL of a sample of 11 solar-type T Tauri
stars in 9 systems. We use these observations to probe the circumstellar
material within 1 AU of these young stars, measuring the
circumstellar-to-stellar flux ratios and angular size scales of the 2.2 micron
emission. Our sample spans a range of stellar luminosities and mass accretion
rates, allowing investigation of potential correlations between inner disk
properties and stellar or accretion properties. We suggest that the mechanism
by which the dusty inner disk is truncated may depend on the accretion rate of
the source; in objects with low accretion rates, the stellar magnetospheres may
truncate the disks, while sublimation may truncate dusty disks around sources
with higher accretion rates. We have also included in our sample objects that
are known to be highly variable (based on previous photometric and
spectroscopic observations), and for several sources, we obtained multiple
epochs of spectroscopic and interferometric data, supplemented by near-IR
photometric monitoring, to search for inner disk variability. While
time-variable veilings and accretion rates are observed in some sources, no
strong evidence for inner disk pulsation is found.
