If you want to make PDF book from your tweets, tweetbook is a web application that will help you to create PDF book from your tweets.
You can sign up in tweetbook via your twitter account. For make PDF book simply sign up in tweetbook via your twitter account then you will get a download link. Tweetbook help you to create XML file for back up your tweets. Tweetbook is allowed only to convert 3,200 tweets into PDF book.