I agree with you on the tweeters and facebook posters - honestly, I never understood that obsession (hence, the rolling eyes emoticon in my prior post).
Depending upon your hotel, the conceirge is not always open (especially due to bad economy and budget cuts), so if you get back from the parks late there may not be one there until the next morning. And if the hotel has a business center, it will probably close at 6 or 7 PM. Therefore, I bring a laptop, but it stays in the hotel room.
And as for pets, I'm guessing you don't have one or had one, but some people get really attached to their pets like they're members of the family. Some times, in order not to feel guilty about leaving a pet behind, just seeing they're okay is enough to assuage any guilt about leaving the pet behind. I have two married friends that did this with their 18+ year old cat.
And for family emergencies, I would not rely on any one hopefully relaying such thing hours later when I got back to my hotel room. I was in a meeting at work for two hours once and away from my office phone when that happened and missed one such family emergency. Since then, I now own a cellphone (I had always resisted getting one as I hate seeing people talk on the things all time - in movies, in theme-park rides, and especially while driving!) to ensure I never miss another such emergency if, god forbids, it ever happens again. Rely on somebody to remember to give me that message? Nooo, I don't think so...

And - wow! - thanks for making me think I'm not the only paranoid camera person out there! I back up my pictures from my camera every single night on a trip!!! It doesn't take that long, you're right, but you feel so much safer for doing it!!!