I keep thinking, would it be considered weird/unsexy/pointless/overly cautious, etc. if I actually used one of those?

Depends on the queer subculture; it's a norm in some dyke scenes and not in others. To me, someone who doesn't come pre-prepared with supplies, or ask me upfront if I have any because they left theirs at home, is likely to ping my risk-meter as someone I'm less interested in a casual hook-up with. Safe sex is hotter than many of the possible alternatives.

For pantryslut, I'll loan you the topic of a rant I've never actually written: "WTF can't I buy safe-sex supplies in the drugstore other than in the 'first aid' aisle?" When I can't go to CVS/Walgreens and see gloves and dams right next to the condoms, I think, hmm, someone doesn't think the sex I have is "real," or an STD risk. Or sometimes, hmm, that's patriarchy in action.