Look out for the one that revolutionizes our interaction between PDF's, Word Documents, Web Sites and our need to link all this data together into a personalized social graph of our ideas and how they are linking together. This of course is really what scholars need. They need a way to follow their trails of information, where they got quotes, who they first read about someone and how they got the data. Hyperlinking between all documents on our personal computers is what is needed and will emerge very soon.
I can say more about this idea later but I wanted to put it out there. This is much like what I have said about the lack of data portability of social networks, something that Social Safe is attempting to solve - in a fairly rudimentary fashion. It is a long way to go but the inevitability is that all social networks will operate on the same protocols allowing users to share data across networks.