Psychology

• Changing Minds - brilliant, easy-to-read summaries of practical psychology knowledge.

Integral Theory

• Integral Life - learn about Integral Theory and its many applications to business, science, and personal life.
• Integral News Blog - elegant writing on various explorations of Integral Theory.
  

Travel

• Volunteers for Peace - volunteer internationally for cheap. Most projects 18+ years.
  
• Gotobus.com - find cheap bus tickets between major US cities.
• Google Maps Pedometer - mark a jogging route on Google Maps and measure its distance.
  

Language

• eTandem - find e-penpals for mutually practicing each other's native languages.
  
• Lingva Prismo - multiculturalist site celebrating and informing on linguistic diversity.
• Lernu - learn the easy language Esperanto for free and network with other students.

Sci / Tech

• Native Energy - support clean energy retroactively by purchasing effective carbon offsets.