Eight examples of the type of line-profile variability detected in our sample of 54 fast-rotating O-type stars. In each panel, we indicate the name of the star, its spectral classification, the number of available spectra, the measured v sin i and RV_PP, and the visually assigned classification within the following categories: LPV, SB1, LPV/SB1?, LPV/SB2?, and clear SB2 systems. We also include in the various panels the (much narrower) Na Iλ5890 interstellar line that we use as a sanity check to make sure that the heliocentric correction has been adequately applied to each spectrum in the time-series. Stars are sorted by spectral classification.