I'm not sure what form this challenge will take for me. I can safely say that like Dave, I will not count books in my 100 things. I will probably also not count craft supplies, since I have more than 100 things right there. Both of those categories, books & craft supplies, may collectively count as one item each. I can see stuffed animals also getting its own category, which would leave me with 97 things. :)
I'll also be excluding shared things: our car & furniture, for example, do not count towards my personal 100 things. I am entertaining the thought of going through our kitchen and reducing our utensils, gadgets, etc to 100 things. And the same thing in the bathroom. But we shall see.
I'm planning to start this adventure on June 1st. Stay tuned & I'll keep you posted.