In a moment of wistful clarity, Mrs theWeir asked "do you think when babyB is older, we'll call her in for her tea by twitter or something?".
What a great question.
Given that babyB is a good few (9?) years off from having a mobile device capable of online interaction (what ever that device might be/look like or cost) I'm not sure we can answer it yet.
However, my guess is that with all the online applications like twitter and facebook being *so* open with their APIs it's leading to online profile management tools (like Seesmic and Tweetdeck) that the service we use will be secondary to the kind of control it gives is.
Those preparing food (or perhaps even the technology being used to prepare the food) can broadcast a "food ready in x minutes" message. With everyone being tracked using GPS (or RFID, where everything is aware of where it is, who & what is around it?) then the device will be able to suggest when you need to leave in order to arrive on time. Imagine that. You're playing on the swings and the cooker sends you a message to say that you should leave in 4.3 minutes so you've got enough time to walk home, wash your hands and get to the table for when it's ready.
(some would say walking is soooo last decade, but there's somethings we do now that are worth keeping, right?!)
Needless to say, I didn't use all of that in my answer to the original question or I'd have been asked to stop talking and get on with something more useful.
What do you think the future holds?