Tweetflick - Save, organize & find Tweets to get the most out of Twitter
TweepsBook - A better bookmarking tool for power Twitter users that you can use to filter, organize and bookmark tweets on your liking.
Bookmark OS - Bookmark OS is like Mac or Windows optimized for bookmarks.
My Twitter Bookmarks - Easily categorize your twitter bookmarks to be read later
ilo - Premium Twitter analytics
Siimpl Bookmarking - Start collecting and organizing what interests you