Interfaces are everywhere. Every time we interact with something in order to achieve something else we are using an interface. This statement is intentionally vague to represent the fact that this can take an almost unlimited number of forms. Interfaces between humans and machines are cleverly called HMI’s (Human-Machine Interfaces). Computer Interfaces are characterized today by the use of GUI’s (Graphical User Interfaces). However these are just the tip of the iceberg in terms of interfaces, even within their own classification. Wikipedia lists 20 different types of interfaces and this is not meant to be an exhaustive list. There is a whole spectrum of interfaces from cryptic CLI’s (Command Line interfaces) that require the user to learn abstract commands to what are called Zero-Input Interfaces which attempt to ascertain what the users want without any direct input, through the use of sensors. I will illustrate several of these types of interfaces with the following examples.