I occasionally like to answer other peoples' questions, and when I solve a difficult problem, I like to share it with the world.
English Language & Usage
Q&A for linguists, etymologists, and serious English language enthusiasts
Meta Stack Overflow
Q&A for meta-discussion of the Stack Exchange family of Q&A websites
Programmers
Q&A for professional programmers interested in conceptual questions about software development
User Experience
Q&A for user experience researchers and experts
Area 51
Stack Exchange Network staging zone, where users come together to build new Q&A sites
Physics
Q&A for active researchers, academics and students of physics
Drupal Answers
Q&A for Drupal developers and administrators
Electrical Engineering
Q&A for electronics and electrical engineering professionals, students, and enthusiasts
Game Development
Q&A for professional and independent game developers
Mathematics
Q&A for people studying math at any level and professionals in related fields
Cross Validated
Q&A for statisticians, data analysts, data miners and data visualization experts
Theoretical Computer Science
Q&A for theoretical computer scientists and researchers in related fields
French Language & Usage
Q&A for students, teachers, and linguists wanting to discuss the finer points of the French language
The Workplace
Q&A for members of the workforce navigating the professional setting
Biology
Q&A for biology researchers, academics, and students