Three pictures are included to the left, running on a slide show. The first I will discuss is the house created for my cats. Its a basic style house: 2 floors with a front door, a single light on each floor (provided by a "night light"), windows on each wall on both floors. The location of the cat house inside my house is next to an air vent, so I constructed a cardboard duct to direct the vent into the cat house on each floor. The entire structure is supported only by some form of cardboard and hot glue.
The next project is a computer stand for my laptop. It is also only carboard and hot glue. It is preciously cut and glued to perfectly hold my laptop, slightly inclined for easier typing. All the ports are accesible while it is on the stand, even the DVD drive. There are three cutouts, one an each side, for airlfow. As an extra I wired three micro case fans to a modifed USB connector to provide extra cooling power.
My last design is a two-level shelf I used in college. We had limited storage space and I desired more shelves. Again using only carboard and hot glue, I assembled the shelves. It was mounted to the underside of my lofted bed. For the attachment I used string, popsicle sticks and a plastic package strap. It could be mounted or removed within several minutes and easily held 30 pounds for the length of 2 semesters without issue.