Although I'm not nearly thin or tattooed enough to wear these holster bags from Skin Graft in their suggested manner—shirtless, sexy, and smoldering—they would make great little gadget bags for those who can pull off the whole not-quite-gothy/not-quite-geeky look that so many of you young internerds seem to be doing these days. (Let's call it "shellbent-for-leather.") They're small enough they might be able to be worn under a jacket without issue, although I don't see any practical way to wear them under a shirt. And you wouldn't want to anyway, unless all your gear is sweat resistant.
Prices are around $80 for canvas models, but go upwards of $200 for the ornate leather and brass versions.