In this project, modifiers were used on simple objects right up to the final object. This allowed the creation of a more complex object while retaining the editability of the simpler objects. However, leaving modifiers unapplied becomes undesirable when objects become too complex. Having to rebuild an object every time an edit is made can crash a computer.

For fun, try to see how quickly Blender will slow down, and maybe try to crash it, by making several cubes and adding a Subsurf modifier to increase their polygon count. Then Boolean the smoothed cubes together, but don't apply the Boolean modifiers. Add more and more Subsurfed cubes and add them to the Boolean object. Then start moving around and editing the cubes to see when performance becomes choppy. It may be surprising how little it takes, depending on your system:

Also, with the measurements of an SD card available, any object can be turned into an SD card holder. Why not make an SD holder key chain or an SD holder that clips to a breast pocket? Add an SD holder to an octopus-shaped pencil holder or any model downloaded online to turn decorative items into something functional. The possibilities are endless!