One of the seeming obstacles to having scheduled informal seminars on chat is the extra work, probably mostly for the leader of the discussion (should there be one), in presenting ideas on the chat page. One person comapred this to Latexing seminar notes, pointing out this was not much fun.

My friend Dmitry pointed out that there are what he called "scribblers," a pad with a stylus, where one can just write or draw, then create a pdf or jpeg and post that. This may or may not be pleasant enough to induce established mathematicians to agree to participate in such a thing.

What are other devices/services that might make, say, real time posting to Chat less of a chore?