1. General Web Design Conferences
  2. UI, UX, & IA Conferences
  3. JavaScript & Ajax Conferences
  4. Graphic Design Conferences
  5. Mobile Web Conferences
  6. Back-End Programming Conferences
  7. Ruby on Rails Conferences
  8. Flash & ActionScript Conferences
  9. SEO & SEM Conferences
  10. Marketing & Social Media Conferences
  11. Technology Conferences

via smashingmagazine.comAn inspiring and extensive list of web events around the world. Just added Evento Blog España and Plugg in the comments.