What to do with light bulbs?

Light bulb An occidental kitchen, classic, with postcards, boxes and... this lighbulb. Why would people keep this? To have it up one's sleeve if another one breaks? Actually no, the bulb is sitting there because the owners do not know where to put it. In a 21st century society where you cannot trash anything (especially in Switzerland), when you don't know how to toss something, you preciously keep it.

Why do I blog this? thinking about practices related to electricity for my course/lecture in Paris tomorrow.