I've been reading Donna Haraway's "Cyborg Manifesto" as closely as I can recently as I'm grappling with the potential of her metpahor for suggesting feminist technology productions, especially with respect to HCI. One question it has prompted that is unanswered right now is how and when technologies actually are used to strengthen ontologies of gender by "moppping up" boundary cases. Certainly sex assignment and disambiguation at birth is one example. I suspect you can argue that cosmetic surgery is another, medical textbooks often feature ideal female and male facial forms that are divergent just how you'd expect (jawlines, for example) (Balsamo, "Technologies of the Gendered Body").

I'd also be really interested in a theory explaining when gender "purification" happens rather than gender subversion. I have a feeling it might have something to do with how public the gender display is and how permanent the technological enagement is. For example, a highly permanent intervention like plastic surgery is far less likely to experiment with resistant interventions that cross into the "opposite" gender's space than fairly temporary or undoable experiences like piercing and MUDding.