Raindrop.io - All your articles, photos, video & content from web & apps in one place.
Tweetflick - Save, organize & find Tweets to get the most out of Twitter
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
Twitter Bookmarks - Create shortcuts to your favorite users/tweets on Twitter
Linker - Cloud based bookmark manager
TweepsBook - A better bookmarking tool for power Twitter users that you can use to filter, organize and bookmark tweets on your liking.