Not overly high tech but such a good fit for the culture and extremely convenient:
Self-filling, self-warming baths
Put the plug in during the day, press the button to fill the bath at the remote keypad in the kitchen. Baths fills and a little jingle announces that the bath is ready at the perfect temperature.
Yeah, I've got a self filling one. Nice to run a bath without even getting out of bed. Although if you forget to put the plug in first, you'll arrive to an empty bath.