I'm blogging this from the 1730 GNER train from London Kings Cross, hurtling back up north at over 100mph. I have wi-fi, I have a power socket, I have an iPod containing 10,506 tracks, and I have a cold can of Stella. w00t!
The wi-fi service is OK. A bit temperamental, but OK - I'd say it's akin to using a 56K dial-up. Modern AJAX-driven web apps like GMail are responsive and perfectly usable. Outlook synchronization (Exchange server over https) is a bit slow, but that's only to be expected and the offline caching of Outlook 2003 makes this fairly usable too. To be honest, the thing I'm having most difficulty with is typing whilst rattling along at such speeds (I'm on one of the peak-time trains which doesn't stop between Peterborough and York).
Oh, I have a little pop-up web window showing me the train's current location on a road map. That's cute, not dissimilar to the flight path screens you get on some jumbo jets (I find those things quite hypnotic - especially if we end up circling in a holding pattern for a while before coming in to land).
I have to confess that I had initial problems activating the wifi (you have to pay for the privilige in standard class - £4.95 an hour). A screen appeared telling me that my credit card was debited, but no password was issued, and to call an 0845 helpline. Hmmm. But, to GNER's credit, the lady on the helpline did a sterling job (after blaming the issue on WorldPay) - asked for my IP address, MAC address, and mobile phone number, as well as details of the train on which I'm travelling, and called me back a few minutes later with the necessary passcode. After that it's been plain sailing. Were I being cynical, I could ask "what if I hadn't had a mobile phone with me, on which to call the helpline?", but then the chance of someone who wanted to use the internet on a train not also being the kind of person who feels naked without a mobile phone is pretty slim.