It is particularly dangerous to generalize when it comes to Twitter and claim that the vast majority of content there is nothing but a heap of senseless rubbish. That could be applied to the Internet as a whole.
For each useful site you will find a couple that are a waste of time, but that should not detract from the fact that the useful sites can make a life-changing difference. The same applies to people to some extent – how many individuals do we meet on a daily basis, and how many actually teach us a life lesson that we are grateful for? Not that many. But not that few, either.
Coming back to Twitter, there are streams that deserve to be treasured for posterity. A case in point: the tweets from the Queen of Jordan, Rania Al Abdullah. She lets users know about her views on society as a whole, and what can be done in order to improve the world we live in. She also provides insights on her daily activities as a Queen, including a timeless tweet that has been around detailing her meeting with the Pope.
This service, then, will let anybody take a Twitter stream and have it turned into a PDF document. This way, anybody can chronicle his or her Twitter existence, and learn about the activity of notable Twitterers and what has brought them into the limelight.