UI Design Webzine

 http://www.uidesign.net/ Articles on interaction designers, book reviews, editorial and interviews.

Usability News

 http://www.usabilitynews.com/ Information in usability and human-computer interaction.

Usability Views

 http://www.usabilityviews.com/ Articles classified by site, date, title and popularity.

Useit

 http://www.useit.com/ Jakob Nielsen's alertbox, reports and books on usable information technologies.

User Interface Designs

 http://www.uidesigns.com Discussion of UI and interaction design. Design examples, forums, and list of related readings.

User Interface Programming

 http://home.online.no/~pethesse/ Articles, books, source code and links about user interface programming under Microsoft Windows.

What You See Is What You Deserve

 http://www.daemonnews.org/199812/d-advocate.html A column from the BSD Unix "Daemon News" e-zine about how GUIs are not always the way to go.