These days, it is quite awkward and ineffective to start talking with strangers without knowing if they share any interests. So, here is an idea that would help find strangers that share your interests while in public while off-screen, and make new friends relevant to our interests.
Imagine rectangular colored pieces that clip into a chain or a layer depending on whether you clip them along the longer or the shorter edges. The other side of these pieces would have clipping mechanism to attach them to the ends of specially made necklace or shoulder-marks, or directly to clothes. This would enable people to buy these pieces of different colors in batches and combine them into patterns they like to encode some information about themselves.
This would work quite simply: if one day you want to say that you're particularly interested in astronomy, physics, math, biology and chemistry, you would arrange the pattern on your necklace or shoulder-mark to represent that, and wear it in public, enabling others to see what you might be interested in talking about, and making it easier to find friends of shared interests.
For example, having 8-colors, it would make sense to have special tri-color codes, enabling to represent 512 possible areas of interest (could extend if set is too small, e.g., 4 or 5-levels would enable to represent deeper more specialized subject domains). We could use combinations to represent each of interest, for example, astronomy = [black, violet, blue], biology = [blue, green, yellow], etc., and so on.
