Padlet - Visual boards for organizing anything.
Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Pinterest - Pinterest is a visual discovery tool that you can use to find ideas for all your projects and interests.
Tagpacker - A free tool to quickly collect, organize, and share your favorite links.
Stample - Share bookmarks, articles, files and notes.
Diigo - Diigo is a powerful research tool and a knowledge-sharing community