We're sad that after all these years, the only place QR codes are actually useful is still good ol' Japan (where they're everywhere). That said, San Francisco has recently dabbled, and there are readers available for just about every mobile platform (including iPhone)-which you'll have to make sure all of your friends have installed if you're going to wear one of these. The $20 patch points to a proxy server which redirects phone browsers to the URL of your choice when someone takes a photo of your shoulder, back, um, wherever. Which means you can take them to your innocent little blog, or perhaps something a bit more nefarious. You wouldn't do that though, would you? [p8t.ch via Pocket Lint]