Here is an article talking about Interaction designers; what they do exactly and how to go about becoming an interaction designer.

http://www.cooper.com/newsletters/2001_06/so_you_want_to_be_an_interaction_designer.htm

Excerpt from "So You Want To Be AnInteraction Designer" by Robert Reimann:

Interaction Design is a design discipline dedicated to:
- Defining the behavior of artifacts, environments, and systems (i.e., products)

...and therefore concerned with:
- Defining the form of products as they relate to their behavior and use
- Anticipating how the use of products will mediate human relationships and affect human understanding
- Exploring the dialogue between products, people, and contexts (physical, cultural, historical)

Interaction design is also a perspective that approaches the design of products in several different ways:
- From an understanding of how and why people desire to use them
- As an advocate for the users and their goals
- As gestalts, not simply as sets of features and attributes
- By looking to the future-seeing things as they might be, not necessarily as they currently are

Given these definitions, interaction designers must:
- Learn new domains quickly
- Solve problems both analytically and creatively
- Be able to visualize and simplify complex systems
- Empathize with users, their needs, and their aspirations
- Understand the strengths and limitations of both humans and technology
- Share a passion for making the world a better place through ethical, purposeful, pragmatic, and elegant design solutions