Most useful:

LEO - Dictionary
Wikipedia - Rules

WetterOnline - Nuremberg weather
WetterOnline - Bavarian weather radar
Bayerninfo - Staubarometer / Radnetz

Oahu / Molokai - Weather radar

Nuernberger Nachrichten - Nuremberg newspaper
Spiegel - Online magazine
N-TV online - German newsticker
Heise online - German IT newsticker

Open-source libraries:

ITK - Insight Segmentation and Registration Toolkit
DICOM OFFIS - Free DICOM library
libcURL - The cURL library
Pthread-win32 - POSIX threads for Windows
OpenThreads - OSG Thread Abstraction
ODE - Open Dynamics Engine
Gerris GFS - Free Flow Solver

Open-source tools:

Emacs - Editor MACroS
VLC - Video Lan Client
Cygwin - GNU + Cygnus + Windows
Firefox - Trash IE
PuTTY - Free SSH client
Gimp - Free Photoshop
Inkscape - Free Illustrator

Graphix libraries:

OpenGL - Open Graphics Library
OpenGL - FreeGLUT
OSG - OpenSceneGraph
libJPEG - JPEG implementation from IJG, the Independent JPEG Group
libPNG - Free replacement for GIF
netPBM - Free PNM image standard
ImageMagick - Free image manipulation tool kit
CIMG/GREYCstoration - Free image denoising tool
Squish - Free DXT compression library

Graphix conferences:

Siggraph - Special Interest Group Graphics
EG - Eurographics
IEEE Vis - Main visualization conference
Eurovis - Nice visualization symposium (former VisSym)
WSCG - Winter School of Computer Graphics

Geographic software:

VTP - Virtual Terrain Project
VTP - The regular VTP mailing list
VTP - The *nix VTP mailing list
GDAL - The libc++ of geographical development
PROJ.4 - Geographic projection library
libgeotiff - GeoTIFF image library
Shapelib - ESRI shape file library
Triangle - Delaunay triangulation library

Geographic links:

Open Street Map - Open map browser
Wikimapia - Geographic Wiki
Speedtest - Geographical bandwidth test

Slashgeo - Geographical /. clone
GLCF - Global Land Cover Facility
SRTM - Space Shuttle Radar Topography Mission
ASTER GDEM - Advanced Spaceborne Radiometer Global DEM
Smith and Sandwell - Global bathymetry
Soest - Coastal imagery of Hawaii
NASA Blue Marble - Earth composite collection