  We illuminate dynamical properties of Kuiper Belt Objects (KBOs) in the 3:2
(``Plutino'') and 2:1 (``Twotino'') Neptunian resonances within the model of
resonant capture and migration. We analyze a series of numerical integrations,
each involving the 4 migratory giant planets and 400 test particles distributed
throughout trans-Neptunian space, to measure efficiencies of capture as
functions of migration speed. Snapshots of the spatial distribution of resonant
KBOs reveal that Twotinos cluster +/- 75 degrees away from Neptune's longitude,
while Plutinos cluster +/- 90 degrees away. Longitudinal clustering persists
even for surveys that are not volume-limited in their ability to detect
resonant KBOs. Remarkably, between -90 degrees and -60 degrees of Neptune's
longitude, we find the sky density of Twotinos to nearly equal that of
Plutinos, despite the greater average distance of Twotinos. We couple our
findings to observations to crudely estimate that the intrinsic Twotino
population is within a factor of 3 of the Plutino population. Most strikingly,
the migration model predicts that more Twotinos may lie at longitudes behind
that of Neptune than ahead of it. The magnitude of the asymmetry amplifies
dramatically with faster rates of migration and can be as large as 300%. A
differential measurement of the sky density of 2:1 resonant objects behind of
and in front of Neptune's longitude would powerfully constrain the migration
history of that planet.
