Toy #2: brown paper packages, tied up with string... BOXES!!!
A building material that is free and relatively easy to find... and can lead to endless creations - some indoors, others outdoors.
Consider doing this for a Christmas gift: get a box - as big as you can find - and fill it with some extras, like scrap pieces of fabric, a set of markers, scissors, and some colourful duct tape - and see what happens.
Here are some video resources for inspiration. First off, Caine's Arcade, an inspirational story about a movement that has inspired creativity and innovation.
If you'd like to add an inspirational book to your gift-box, consider this one (same author as Not a Stick): Not a Box by Antoinette Portis.
* colour in your box
* a 73-box fort in the "box room" of the house
And some visual inspiration: some daunting, some totally do-able: