This is easier than water balloons - and the fun can go on for hours! What a FANTASTIC idea! GREAT PRESENT IDEA
FREE download - GENIUS HOUR project proposal
Genius Hour (also known as Time) is an inquiry-based learning project in which students work on individual projects focused on their passion.
This Elementary Life blog: My experience with Genius Hour
3 Rules for Genius Hour
guiding questions and board letters "Genius Hour"-- Passion Projects
Getting Started with Genius Hour | ABCs with Mrs. B
Helpful article (and infographic) on the anatomy of the PBL process.