Head on over here between 2 and 4pm EST today, Friday February 27.
UPDATE: Reddit is not allowing me to post. On my own IAMA. Granted, this IAMA was set up by someone else, who said he had duly submitted my handle (Nina_Paley, created a week ago) to the mods. But it didn’t work. I was on the calendar, but I can’t respond to questions. I am not happy about this but mods aren’t responding, so I give up. You can AMA on Twitter instead.
UPDATE 2: after half an hour the problem was corrected, and I went back and answered questions.