Start a new business In 3 day.
Day 1 - Pitch your idea and build a team / listen and find a cool team to join
Day 2 - Plan and start develop your idea in to a working prototype
Day 3 - Present your prototype to a panel of experts who will give you feedback.
Why do this:
Find your future business partner (You can find out in 3 days if they are all talk)
A Demo is the new standard for pitching to investors (Yes, that means a prototype)
3 days watching TV or 3 days that could change the course of our life forever (no joke)