Hi Johnny58, to answer your question, the Pin Trading Nights aren't really an "event"; Disney lets us pin traders use one of the conference/ballroom (usually at the Paradise Pier Hotel, ground floor) for pin trading (no charge). Cast members wearing lanyards are there to trade with, and they'll have a few preview boards showing pins that Disney plans to release within the next couple of months (we drool in anticipation, lol). I can't remember if they do trade boards anymore (I hate standing in line so I never pay attention to that possible aspect of PTN). They used to have a part of the room sectioned off for kids only, but I think they did away with that, unfortunately.
It's a fun night, bring your pins and either "work the room" or plunk yourself down at one of the tables.