While I sometimes find people talking on cell phones annoying, I have to admit that they give my family so much more freedom than we ever had while touring WDW in the past. Now, our teenager can head to DQ, dh can take our other ds on the coasters, and I can take our dd to see the princesses...without having to worry too much about anyone. We're not folks who like to "chat" on the phone, so we won't be the party the neighboring table calling all of our friends at home to loudly report on our trip; but you might find dh sitting on an out-of-the-way bench taking an emergency call from his office.
As far as tired children out too late....What about tired, cranky parents? Our 3 kids just won't stop when they're at WDW!!! It doesn't help that they're normally night-owls at home, too. I'm the complete opposite. Grrrrrrr!!