I still send postcards, but it's getting harder and harder. The choices are terrible and it's difficult to find stamps. Plus it costs a lot! Email is definitely cheaper. Instead of calling people, I now use web-based messaging systems to make meeting points. But I need wi-fi to do it.
LUGGAGE
I will never - never - use a backpack again. The days of searching through a 20kg pack of clothes that you didn't actually need to bring half of to find the one clean T-shirt at the bottom, which smells like all the other dirty T-shirts anyway, are over. I love my suitcase.
ACCOMMODATION
The internet has also changed the way we book hotels. Gone are the days of turning up somewhere and hoping for a room, happy to share a dorm with 25 other snoring, wind-producing, inconsiderate eejits, some of whom have no qualms about having sex in the same room as an audience. I use third-party booking sites almost exclusively, even in New Zealand. For my September New York trip, I'll be using Airbnb.
LAUNDRY
Along with wi-fi, my other new obsession is clean clothes. I never thought I would do hand-washing in hotel rooms, but there you go.
MAPS
I still love using a map, because I'm directionally challenged. But on the trains in London, people had the Tube map on their phones. Google Maps is, of course, easier. But see above re: wi-fi.
UBER
Catching cabs is for suckers. But Uber's not everywhere of course and - once again - you need that blasted wi-fi.