Paper clips are usually made out of wire. A paper clip can be useful when working with many things, like computers. The metal wire can be made straight with a little bit of work. Some things have buttons that cannot be reached by fingers if the people who make the device do not want users pressing them accidentally. Most CD-ROM drives have small buttons like this to eject the CD-ROM if there is not any power. A paper clip bent into a 'U' shape can be used to create a short circuit to start a computer if there is no power button.