As for the QR code, that one might get _really_ awkward, when someone is standing on the other side of your screen trying to scan your laptop instead of saying “hi” ;)

I think it could gain more traction if there was a standard format – perhaps a template sticker saying “I like to talk to people about… [blank]” on which you could then write your current projects and interests.

Perhaps adding a QR code to the back of your laptop with a URL to your website would also work…