  We propose a new method for detecting a charged (pseudo-)scalar at colliders,
based upon the observation that its Yukawa coupling to charm and bottom quarks
can be large due to a significant mixing of the top and charm quarks. After
analyzing the typical flavor mixing allowed by low energy data in the topcolor
and the generic two-Higgs doublet models, we study the physics potential of the
Tevatron, LHC, and linear colliders for probing such an s-channel charged
resonance via the single-top (as well as Wh^0) production. We show that
studying its detection at colliders can also provide information on the
dynamics of flavor-changing neutral current phenomena.
