I received this article via the
InfoSec News mailing list (excellent mailing list BTW). It takes a unique look at why open source software (i.e. Linux) is inherently more secure. It's not the same old tired argument of many eyes freely looking at and modify open source code versus the fewer eyes of proprietary code. It covers several more, IMHO, valid arguments, including the modular nature of Unixish OSes, the nearly ritualistic habit of not using root for non-administrative tasks, and the transparency of the Unixish open source OSes.
It's a good, short read.
http://theregister.co.uk/content/55/36033.html