The official team registration site for the IoTHackDay has been posted on Devpost! If you're interested in participating in the actual IoT Hack Day, sign up here:
If you or your friends/family are just curious and would like to attend and see what the teams have built. Register for the IoTHackday 2016 Final Pitch Showcase at 8:00pm! (https://www.eventbrite.com/e/iothackday-2016-final-pitch-showcase-tickets-28623797549)
You don't have to join a team beforehand to sign up. You can just register at the site above as a participant, and then show up. You can join a team the day of, you can join the random team (http://devpost.com/software/2016-iothackday-catch-all-team), or you can come to the meet & greet event (http://www.meetup.com/iotfuse/events/233811268/) if you want to network to try to join a team ahead of time.
If you do sign up as a team ahead of time, there are all sorts of benefits...including promoting your team to the whole IoTFuse group.
Here's the lineup of teams thus far:
Quadcopter Stunt Pilot Game (http://devpost.com/software/quadcopter-stunt-pilot-game)
Magic Bluetooth House (http://devpost.com/software/magic-bluetooth-house)