Just some links that I consider as usefull...

• BD-Club Ilmenau
  ...a location were I once spent a noteworthy part of my spare time
  
  
• Greenpeace
  ...one of the NGO's I consider important and which I support
  
  
• Amnesty International
  ...another NGO that I think it does a good job
  
  
• Debian
  ...if you should look for a new operating system to power your PC
  
  
• Lonely Planet
  How to travel in a strange country
  
  
• Telepolis
  Reliable as well as critical news from politics, science, culture and society
  
  
• Fotolia - royalty-free images
  Stock photography for everyone - her you can get som of my work as well
  
  
• iStockphoto - more royalty-free images
  More stock photography also offering some of my contributions