Today’s invention is a name badge or other physical label which can be created, modified or recycled very rapidly.
Imagine a mat of stiff, open-weave fabric, about the size of a business card.
This can be fed into a small embroidery machine which will loosely sew a user-specified message.
An algorithm works out the most legible way to reproduce some text and/or graphical elements, using a single strand of colour-contrasting thread. When you leave a meeting, simply pull on one end of the thread for the message to disappear (thus avoiding the confusing experience of having strangers address you later using your first name).
As well as name badges for conference-goers, this could extend to the creation of one-off messages on T shirts or tents.