Evidence for B+->(K)over-bar(0)K(+) and B-0 -> K-0(K)over-bar(0), and measurement of the branching fraction and search for direct CP violation in B+-> K-0 pi(+)

We present evidence for the b -> d penguin-dominated decays B+->(K) over bar K-0(+) and B-0-> K-0(K) over bar (0) in 227x10(6) Upsilon(4S)-> B (B) over bar decays collected with the BABAR detector. We measure the branching fractions B(B+->(K) over bar K-0(+))=(1.5 +/- 0.5 +/- 0.1)x10(-6)(< 2.4x10(-6)) and B(B-0-> K-0(K) over bar (0))=(1.19(-0.35)(+0.40)+/- 0.13)x10(-6), where the uncertainties are statistical and systematic, respectively. We also present improved measurements of the charge-averaged branching fraction B(B+-> K(0)pi(+))=(26.0 +/- 1.3 +/- 1.0)x10(-6) and CP-violating charge asymmetry A(CP)(K(0)pi(+))=-0.09 +/- 0.05 +/- 0.01, where the uncertainties are statistical and systematic, respectively.