I believe "swivelback" cufflinks are not the desired type--I have heard that both ends of the link should match, like the barbell or coin models.
However, are swivelbacks ever acceptable? I have some of my father's that are quite nice, but they are of the swivelback variety. I saw someone wearing double cuffs that had been fastened in such a way that the edges of the cuffs weren't meeting, but overlapping--therefore, the backs of the links weren't visible, as they were inside the cuff, against his skin. Looked a little weird to me, but I guess it would sove the problem of displaying the "functional" side of the cufflink.
Is that just dumb?