Inkscape

A Guide to Inkscape
Online book describes features and tools, giving examples of their use.
http://tavmjong.free.fr/INKSCAPE/

Inkscape LaTEX Extension
An extension to enable a combined export format with text in a LaTeX picture environment and everything else as EPS. Background information, screenshots, download, and release history.
http://richard.henwood.googlepages.com/inkscapelatexextension

TexText
Inkscape extension to add editable LaTeX text objects to a document. Includes overview and download.
http://www.elisanet.fi/ptvirtan/software/textext/

Wikipedia: Inkscape
Article gives an overview of features and history.
http://en.wikipedia.org/wiki/Inkscape

Linux.com Review: Inkscape 0.45
Review of the new release, with evaluation of its new features, speed, and usability enhancements. <small>(February 23, 2007)</small>
http://www.linux.com/article.pl?sid=07/02/23/1639217