[joshu]

It is like the floppy disk icon for saving.

Someday hailing a cab will be a button that says "hail a cab" and no more.

There should be a word for this.

[wickedchicken]

> There should be a word for this.

Roughly, http://en.wikipedia.org/wiki/Skeuomorph

[Simucal]

Anachronism maybe?

[Evbn]

Skeuomorphic