Null has written for numerous publications, including Wired, Business 2.0, PC World, Men's Journal, San Francisco Magazine, Yahoo! Internet Life, Working Woman, San Jose Magazine, The Austin Chronicle, and The Austin American-Statesman. He is also the author of two books: Five Stars! (2005, Sutro Press), a manual for aspiring film critics, and Half Mast (2002, Sutro Press), a novel. A list of Null's publications is available at his website.

Prior to writing for Yahoo!, he was the founding Editor in Chief of Mobile PC Magazine. He also served as editor in chief of New Architect, Executive Editor of Smart Business magazine, and Managing Reviews Editor of LAN Times magazine.