useful Social netwoking sites & Discussion forums

Ask anything you want you will get an answer. The best part is that you may get some answer from professionals too.
• Quora online discussions
Cowbird is the most beautiful place in the world to tell stories through pictures.
• Cow Bird
Stack Overflow is a question and answer site for professional and enthusiast programmers.If you are not a programmer , Then I should say sorry for including this website here.
• Stack Overflow
If you had the chance to speak to a million people, what would you say? List serve is a new way of expressing your feelings with thousands of people through e-mail
• The List Serve
Create stories using social media. Turn what people post on social media into compelling stories. Collect the best photos, video, tweets and more to publish them as simple, beautiful stories that can be embedded anywhere.
• Storify
XING is a social network for business and career. Find old acquaintances, new people, jobs, events, companies, and groups.
• Xing
The world's largest collection of life experiences, personal stories, and the people who have had them. Share and connect through your life experiences, or explore new experiences.
• Experience Project
This is not a social n/w nor a discussion forum but I would like to add it here as this site makes it easier to chat with your friends of different social networking sites at one place
• imo instant messaging site