  The latest measurements of the cross sections for singly-produced top quarks
at the Fermilab Tevatron are presented. The small expected signals and the
large, uncertain backgrounds require careful event selection, sophisticated
methods for separating signal events from background events, and data-based
background predictions and fits. Both the CDF and D0 collaborations have solid
evidence of single top production, using 2.7 fb-1 and 0.9 fb-1 of data,
respectively. Both collaborations perform several analyses to measure the total
single-top cross section sigma_s + sigma_t, as well as sigma_s and sigma_t
separately.
