i have often thought it would be useful to be carrying a sign that can be read by anyone passing me in the street.
i know we have notes, but we have to drop them and people have to interact with them to see what they say.
the ability to carry a sign would be handy for a lot of things, like "i am fixing tools for free" or "i'm playing a goofy trading game" or even "i prefer to mine alone".
i do not know how it should be implemented; maybe it would be temporary and timed, or it might expire as you pass to another street. it maybe should cost you something to hold and certainly require a skill or two.
i'm not very fussy about the details, but i do know i have often thought that a sign would be a handy thing to be able to carry.