The frustrations of the 21st century

Here I am on a train, and my PowerBook has picked up a strong wifi signal. But can I use it? Of course not, though I'd happily pay a reasonable fee, if only to be able to blog that I'm "on the train".
It's the same network I encountered once before, Nomad, but whereas first time round I didn't care that I couldn't use it, I was excited to see that it was there, now I'm just annoyed that there's no way of using it.
I contacted them last time and was told that it was experimental, and asked if I would like to test it. I replied that I would, but never heard any more.
Postscript: on the way home I had time to kill at Victoria so logged on to the BT OpenZone network in the bar, surrounded by drunks, bought some more time, then the battery went.