opennap.sf.net - OpenNap - The Open Source Napster Server (abandoned project).
opennap-ng.sf.net - OpenNap-NG - OpenNap successor
opennap-ng.org - OpenNap-NG #2 - Another OpenNap successor - I honestly have no idea which, if any, of those projects is still in active development.
lopster.sf.net - Lopster - Excellent GTK-based Napster client.
debian.org - Debian GNU/Linux - Free (in the GNUish sense of course) Linux distribution, developed by a bunch of voluntary programmers from around the globe.
ubuntulinux.org - Ubuntu Linux. Very promissing Linux distribution based on Debian. Always quite up-to-date due to a constant release cycle of six months.
h07.org - H07 - German Unix/Linux development team.
eff.org - Electronic Frontier Foundation - The "freedom fighters"(!). Non-profit group protecting your digital rights.
xenu.net - Operation Clambake - Fight against the "church" of Scientology on the net.
ology.org/principia - The Principia Discordia - The one and only true bible. All Hail Eris! Hallelujah!
yigg.de - Yigg - German digg.com-Clone - Lotsa interesting news. [German]
pigdog.org - The Pigdog journal - Another news site. :)
dict.leo.org - Excellent German <-> English dictionary.
kiew.org - KiEw - Industrial madness from Northern Germany. Play excellent concerts.
ampedout.net - ampedOut - Streaming Internet Radio station playing EBM, Industrial, Goth, Ambient and all kinds of noisy stuff.
ant-zen.com - Ant-Zen - Record Label producing lots of great Industrial and stuff.
galakthorroe.de - Galakthorrö - Home of Haus Arafna and friends. Industrial like it should be.
adnoiseam.net - Ad Noiseam - Yet another great record label for Industrial, Noise, Ambient and Experimental music.
discogs.com - Discogs - Great database of all kinds of electronic music.
kzsu.stanford.edu/eklein - Another great database of Gothic/Industrial/Ambient/Whatever music.
autobahn-online.de - Very interesting website about german highways with lots of information about their history, the present and planned roads and abandonned projects.
nurburgring.org - Ben Lovejoys website about the "greatest & most challenging race circuit in the world". A must-read for everyone planning to go there. Please read the safety advices and keep in mind that much better drivers than you and me died there.
justgofaster.com - Probably the funniest British website ever created. Ring-related.
julesperry.com/nurburgring - Capture of the Nuerburgring webcam (the last 60 minutes are archived) by VLN/24h-racing driver Julian Perry
touristenfahrerforum.de - Discussion board about Nuerburgring-related topics (especially the public driving sessions) including a section where photographers usually post their pics from the Ring. [German]
wikitravel.org - Wikitravel - free, complete, up-to-date, and reliable world-wide travel guide - Kinda like Wikipedia for travelling
...to be continued.