Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Tagpacker - A free tool to quickly collect, organize, and share your favorite links.
Pinboard - Pinboard is a personal archive for things you find online and don't want to forget.
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
Barkr - Organise bookmarks into collections and then find your favourite websites quickly and easily, using an intuitive search rather than wading through masses of folders.
Pinterest - Pinterest is a visual discovery tool that you can use to find ideas for all your projects and interests.