Ask An Expert – http://www.askanexpert.com/
Covering topics of all kinds, Ask An Expert provides information from real world experts who have volunteered to answer the questions you have.
The site, which is primarily geared to the learner, is suitable for all persons, from kids to parents, from students to teachers.
Some of the subjects covered on the site include aerospace, business, computing, cultural issues, humanities, specific trade information, repair questions, and much more.
All Experts – http://www.allexperts.com/
This site provides thousands of volunteers, including lawyers, doctors, engineers, and scientists, waiting to answer your questions. All answers are free and most come within a day!
Along with providing pointers to experts on a vast array of topics, the site provides directions on how you too can volunteer to provide answers for others.