On my shoulder, perking up when asked like a well behaved, very small butler. 'They' are creating such things - like a dog or cat plugged into Google that knows your mind. Thinking this through I think a couple of AI squirres would do the trick, one red and on my left shoulder, and the other grey and on my right. They can talk to eachother when I'm not around, otherwise they can remind what I've done, what is coming up and what I need to do next. Reading and responding is the measure of the day.