Tweetmarks is a bookmarks tool for Twitter. Do you ever find yourself looking for some link you shared on Twitter? Tweetmarks can keep track of all all links you share, or just those you use a hash tag with (like #apple). If you use del.icio.us for organizing your bookmarks, Tweetmarks can automatically add your links to del.icio.us too! Visit the Tutorials page for how to use Tweetmarks.
Michael Jensen (follow me @mdjensen) creates lots of Twitter tools. You can learn more about Michael Jensen at mdjensen.com.