What proximity is and how to use it in graphic design and web design.
Proximity in Design: Why I Can’t Use My Car’s A/C
Smashing Magazine looks as "creating meaning and patterns through proximity" using the A/C panel on a car as the example to explain the concept.
Design Bascis - The Proxmity Principle
Lesa Snider, writing for Macworld, describes and illustrates some simple ways to employ proximity and improve a page.
Design Principles - Proxmity
NHS Designs offers multiple illustrations of proxmity in design.
Proximity - How to Effectively Organize Your Pages
The Web Design Library discusses the do's and don'ts of proximity in Web site design.