We present evidence for charge correlations of B mesons with
charged particles produced in ppbar collisions at 1.8 TeV.  Such correlations
are expected to arise from pions produced in the fragmentation chain and
from B^** decays.  We measure the efficiency and purity of this flavor tagging
method for both charged and neutral B mesons.  We apply these correlations to
B mesons reconstructed in 110 pb^-1 of data collected with the CDF detector at
the CDF detector at the Fermilab Tevatron Collider.  B mesons are either
partially reconstructed, using the semileptonic decays B^0 -> l^+ D(*)^- X and
B^+ -> l^+ D-bar^0 X, or fully reconstructed, using the decay modes B^0 ->
J/psi K^*0 and B^+ -> J/psi K^+.  Application of this new flavor tagging
method to neutral B mesons yields a measurement of the frequency of the
oscillation B^0 -> B-bar^0.  We obtain Delta m_d = 0.446 +/- 0.057^ +0.034
_-0.031.