This handy clip prints up fast! It is a great demo print of something useful for your friends who want to know what all this 3D printing fuss is about. It's also a great way to use up those last 5 feet of filament.
Set your slicer's line width to exactly 0.5mm and this will print up solid with exactly 2 perimeter lines and no time-consuming infill moves. I'd recommend using a 0.2mm layer thickness (or less), and maybe print a tad hotter than usual to make sure all perimeter lines fuse completely.
I printed these in PLA, but ABS should work as well.