The list of sites that I visit the most. Over time, this list will change depending on my own liking, the topics I'm interested in, etc.

Google's news aggregrator.
Daily news on everything Linux.
An excellent in-depth source of information for everything related to Linux.
IT news from a free software and open source perspective.
Great source of technology news.
Monthly magazine that focuses on how emerging technologies impact culture, economy, politics, and society at large.
The British version of Wired magazine.
Magazine from the renowned Massachusetts Institute of Technology (MIT) dedicated to technology and its cultural and business ramifications.
Monthly American business magazine that focuses on technology, business, and design.
Launched in 1996, this website tries to bridge the gap between the humanities and the sciences in the name of a third culture. Plenty of food for thought here.
Simply the latest scientific research news.
An evolutionary approach to health and disease. Generally linked to the so-called paleo approach to diet.
The best free cultural and educational media on the web.
Perhaps the best compendium of arts and letters information available online to this day. The editor of this site compiles a list of the best articles published on those topics, and links to them. That's all.
Not sure they chose the best name for this podcast (and the related website). It's not what it sounds. Nice collection of articles and audio files with plenty of information and advice on how to become a better man (or, actually, person).
Artículos, documentales, videos, bibliografía... todo tipo de información sobre la filosofía (y las propuestas) del decrecimiento.
Blog written by Massimo Pigliucci, well known author of several books on Stoicism. His blog is full of good information on that classic philosophy, as well as tecniques that can be used to apply it to our modern life.
The website of the American humor magazine. Be careful, some of their "news" pieces sound scarily real.
Parecido a The Onion, pero en castellano y en el contexto español.