The Fallible Ideas Discussion Group is your opportunity to learn more about philosophy, get your questions answered, and contribute your own ideas. It works by email. Join on the Google Groups Website or send a blank email to [email protected] and then reply to the confirmation email.
In order to maintain high discussion quality, there are discussion guidelines which explain how to make self-contained plain-text posts which quote the text you're discussing and respond below it.
If you'd rather just type some words in a website box without worrying about an organized, formatted discussion, then use my Open Discussion web forum.