In this day and age, you'll find most common consumer electronics are coming out with a nod towards internet connectivity. I've read of refrigerators having touch screens and cell phones which can switch to use VOIP when in the presence of WiFi signals. I spent Saturday night at a friend's place where his DVD player can stream MP3s and MPEG video from a networked server, as well as access streaming radio stations on the Internet.
So I don't necessarily think a networked smoke detector would be too bad an idea. I mean, you could probably build radon and carbon monoxide detectors into the same unit, thereby eliminating the need to have like 200 of these obtrusive, beige, round things in the house--I don't think I'd even mind the increase in price. People could check the safety of their houses from work, making sure that everything is ok at home with the kiddies.
But most of all, you could have a frickin' clock so that when the damned battery gets low, it doesn't start incessantly chirping at 4:00 in the morning without the means to get the thing to shut the fuck up!
Thank you for your consideration,
James, who is planning to hit Costco on his lunchbreak to pick up some 9-volt batteries...