This is a cat activity board ( we call it "Fummelbrett" in Germany), which I made for my two cats Mason and Freckles. They were already bored of their cat tree and their usual toys, so I decided to make something new myself. I used a wooden board as basic and cardboard rolls, little boxes, childrens toys, empty plastic bottles and stuff like that for the modules.
First I covered the cardboard rolls and boxes with fancy paper, then I decided where everything should have its place and hot glued all of it onto the board.
To use the cat activity board, you fill the modules with treats. The cats have to fumble them out, which is a little challenge and also a lot of fun for most cats.
My cats really love it, they fumbled out all of the treats in about 20 minutes and kept lookig if there might be more! :)

***I've got the idea for the cat activity board from this site: http://www.katzenfummelbrett.ch/ ( it's under construction at the moment).***

I tried to list everything I used. If you're interested in a how to, let me know - I'd be happy to try. :)