Wi-Fi in Europe.
AT THE risk of huge conceit, I have named my iPads ''Charley'', after the dog that accompanied American novelist John Steinbeck on his discovery of his own country.
His Travels with Charley is a good read, revealing much that remains relevant even today but continues to be generally unknown about the US and what makes it tick.
Steinbeck I am not and do not claim to be but the iPad, now with me in its third generation, has been and is - as Charley was to Steinbeck - my constant, faithful travelling companion.
I have just completed six weeks in Britain and Europe with Charley my only means of emailing, sending text messages, podcasting with Skype, chatting on FaceTime, writing this column, taking, editing and emailing photographs, communicating with my editor, finding my way, booking into B&Bs, checking my bank balance, paying bills back home, watching a movie when the TV was rubbish, listening to ABC 774, reading The Age, checking appointments, keeping track of times and dates, waking to an alarm, reading books and blogs, getting frustrated on Angry Birds, listening to music, surfing the web, reading The Economist and The New York Times - thinking on it, I wonder how I had time to eat.
The myriad apps and the ubiquity of the internet via wi-fi and mobile data networks is the real source of the iPad's power.
Wi-fi is everywhere in Europe; far more than in Australia, Asia or the US. Britain's Openzone has 3.5 million access points and is growing. Free wi-fi is a universal marketing tool for hotels, B&Bs and cafes, including chains Caffe Nero, Pret A Manger and, of course, Starbucks.
Compare that with tools of a young correspondent in Asia in the mid-1960s. There was no internet. I wrote my copy on a portable typewriter that weighed more than airlines now allow as total cabin baggage. In Vietnam, I had to carry my copy from the field to the local telegraph office, where it was sent to Paris by an operator using a Morse key. Paris sent my missive to Cable and Wireless in London, which re-transmitted it to OTC in Russell Street, from where it went, I think by bicycle, to the Herald and Weekly Times on Flinders Street. Telex arrived a little later.
Back then there were only half-a-dozen foreign correspondents in the area but as our numbers grew and US influence came to bear, communications improved, though they remained very slow by today's standards.
When censorship was imposed in Saigon, we correspondents clubbed together and crammed copy, film and cassette tape into a suitcase, which one of us carried every few days to Hong Kong.
Getting it past the police at the airport was quite exciting.
The web, the voracious demands of TV and all the other technology now at our fingertips have changed everything; for better or worse is for you to judge but sometimes minute-by-minute coverage of tumultuous events does not necessarily produce understanding.
My latest MacBook Pro is more powerful than the iPad - a big hard drive, Gigabit Ethernet, Firewire 800, two USB 2.0 ports, Thunderbolt and so on - but for me now (and not always), the iPad does all I need.
I have wi-fi and 3G built in, where the Mac needs a dongle. Bluetooth connects my small Apple wireless keyboard - essential if one needs to do extensive writing - and the two together weigh one-third of the MacBook. I've carried them both in an anorak pocket. I could have used a keyboard-equipped iPad case but the Apple one is sturdier and more convenient, because I can position screen and keys where I want them.
Wherever we have gone, we have seen iPads at work.
In a street cafe in Florence I watched a waiter using a Japanese girl's iPad and Google Maps to show her the way to a museum.
In London, looking for post-theatre supper, we dropped into the White Hart, a pub that for a couple of hundred years has stood where Drury Lane meets High Holborn.
At the far end of the bar, a young man called Owen was running a trivia night for about 40 people using the pub's 50-inch HD TV to play music, show video clips and the text of his questions - all from his iPad.