Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.

Design Principles - An open source repository of design principles and methods

Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.

Facebook Design Resources - A collection of free resources made by designers at Facebook

Qiqqa - Qiqqa is a free research and reference management software. It can be used in many organizational projects from the academic to the personal to the business endeavor. Read more about Qiqqa.

Facebook - Connect with friends, family and other people you know. Share photos and videos, send messages and get updates.