User Centered Design

UserCenteredDesign means making things so that they are maximally usable. User interface which doesn't get in your face.

A good, fast read is:

TheDesignOfEverydayThings by Don Norman.

ISBN 0465067107 from Los Angeles Times: "...makes a strong case for the needlessness of badly conceived and badly designed everyday objects...[T]his book may herald the beginning of a change in user habits and expectations, a change that manufacturers would be obliged to respond to. Button pushers of the world, unite."

Plenty of Web sites on UserCenteredDesign exist, e.g.:

http://www-3.ibm.com/ibm/easy/eou_ext.nsf/Publish/570
http://www.useit.com/