First it was about blogging what you've done, then Tweet & 4Sq what you're doing, now its Plancasting what you will be doing... what next?
This is in relation to the evolving change of the social web, from a reporting medium (such as this blog) to a real-time communication system (via Twitter streams) and then potentially onto a way of scheduling what you're going to be doing.
To try this out I've tried 'plancasting', a site where you say where you will be and when you will be there. The aim being that you can coordiate your activity with others. However not everyone is using these tools yet and to a certain extent the jury is still out on whether the future planning of your activity will gain mass adoption.
Also to be frank... it does kind of take the flexibility out of your plans when you've told all your followers (and therefore potentially everyone and also nobody at the same time) when and where you will be. But who knows... it could become the next big thing...
To perhaps quote the Sci-Fi writer William Gibson might be most apt: "The future has arrived, it’s just not evenly distributed yet"