I'm struggling with the same problems for couple of years now. And not a few people around me have the same problem. That's why I started a project called Togetherise (http://www.togetherise.com) couple of months ago. The main idea is to bring people together when fulfilling some work/idea/project or just to help each other. Portal will offer both knowledge and tools. It is in a development phase right now. I believe it will fill the gap we're all talking about. It is not meant to be used only by developers or designer. It targets all project and people that need help or can offer help through mentoring or coaching. A good team of professionals is already behind this project, so I hope we'll enter beta phase by the end of spring.