With Twournal (currently in private beta) you can immortalize your profound twitterings into an actual paperback book that can include replies and attached Twitpic, Tweetphoto or Yfrog pictures in color or black and white. You have the ability to select which tweets you want to start and end at. You can add a dedication and a custom picture for your front cover. They’ve also added the option to sell your Twournal. Pricing depends on the number of tweets, but books start at $15 or you can get a free PDF.