Yahoo! Answers - Home 
A place to ask questions or answer questions of others.
Q&A Toolbox: 30+ Tools For Questions and Advice
Mashable's list of top 30 How To and question and answer sites
Who's Asking? A Roundup of Q&A Sites - ReadWriteWeb
A clear post listing a lot of the question and answer sites and an opinion on their value.
r_sites.php
Technology Review: What's the Best Q&A Site?
A somewhat simplistic review of several question and answer sites.
=f
Squidoo Homepage
Mixed social media site - create a lens on an area of your expertise
tipstrs -- Tips, tricks, advice, and hints on categorized subjects
Social media site which allows people to provide tips, hints and advice with links to websites for more information
Consumer Ratings and Reviews on RateItAll.com
An opinion and rating websites which reviews and rates businesses and products. Fairly general cross section of products being rated.
WikiAnswers Q&A Community
A place not just to ask or answer questions, but to improve answers, fix spelling errors or improve questions.
Fluther: Tap the Collective
A place to ask or answer questions, with questions becoming more specific to you the more you contribute.