Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Diigo - Diigo is a powerful research tool and a knowledge-sharing community
Pinboard - Pinboard is a personal archive for things you find online and don't want to forget.
Pocket - When you find something you want to view later, put it in Pocket.
Bookmark Sidebar - Adds a toggleable sidebar with all your bookmarks at the edge of your browser window.
ShuffLink - Alternative to StumbleUpon or more like a random link generator on the Windows Phone platform.