(La)TeX Navigator
A (La)TeX encyclopaedia from Loria. Also available in French and German.
CTAN Search
Online search interface for CTAN. Search CTAN for a file or search the TeX catalogue by Graham Williams for a keyword.
Mathematics For Computer Generated Spoken Documents
AsTeR --Audio System For Technical Readings-- is a computing system for rendering technical documents written in LaTeX in audio.
TeX Merchandising
Merchandising for TeX and friends. On-line ordering with PayPal.
The TeX showcase
Edited by Gerben Wierda, it contains examples of what you can do with TeX, from typesetting of scientific papers to music, multimedia, genealogical presentations, dynamic documents…
The TeXability Site
Shows short (mostly single page) documents with immediate access to graphical results and source to demonstrate the power of TeX.