  We reconstruct B+/- -> D K+/- decays in a data sample collected by the CDF II
detector at the Tevatron collider corresponding to 1 fb-1 of integrated
luminosity. We select decay modes where the D meson decays to either K- pi+
(flavor eigenstate) or K- K+, pi- pi+ (CP-even eigenstates), and measure the
direct CP asymmetry A_CP+ = 0.39 +/- 0.17(stat) +/- 0.04(syst), and the double
ratio of CP-even to flavor eigenstate branching fractions R_CP+ = 1.30 +/-
0.24(stat) +/- 0.12(syst). These measurements will improve the determination of
the CKM angle gamma. They are performed here for the first time using data from
hadron collisions.
