There are several websites that let users ask and answer questions about all kinds of topics. Popular tech site The Next Web mentions Yahoo! Answers, Answer Bag, Blurtit, WikiAnswers and Mahalo Answers as some of the places where users can ask and get relevant responses to their inquiries.
Some sites require users to register in order to be able to participate, and they typically organize questions and answers by categories. Some of these sites have developed into full-fledged Q&A-powered communities, where answers with the highest ratings among users get pushed to the top and where, in some cases, a points system is in place to reward the quality of the answers.