We present recent results from searches for single-top-quark production using 2.7 fb^{-1} of data accumulated with the CDF II detector at the Fermilab Tevatron. We select events with one charged lepton, large missing transverse energy, and two or three jets, where one jet is identified as a b-quark jet using displaced secondary-vertex information from the CDF silicon detector. We employ several multivariate techniques which are subsequently combined to produce the most sensitive results to date.