  We present a global analysis of neutrino oscillation data within the
three-neutrino oscillation scheme, including in our fit all the current solar
neutrino data, the reactor neutrino data from KamLAND and CHOOZ, the
atmospheric neutrino data from Super-Kamiokande and MACRO, and the first data
from the K2K long-baseline accelerator experiment. We determine the current
best fit values and allowed ranges for the three-flavor oscillation parameters,
discussing the relevance of each individual data set as well as the
complementarity of different data sets. Furthermore, we analyze in detail the
status of the small parameters theta_13 and Delta_m21^2 / Delta_m31^2, which
fix the possible strength of CP violating effects in neutrino oscillations.
