We went to see one of the Metropolitan Police's helicopters land in the park and show off to all their fans. It was a charmingly low-key event - a bit like an ad hoc fete. The crew described their aircraft as a "transit van in the sky" and made jokes about how it was tough enough for the Territorial Support Group. Then lots of kids pretended to fly it.
I suspect it was that informal because it hadn't been long arranged - we only found out about it because we follow the helicopter on Twitter (@MPSinthesky). They post a combination of glorious photography of London and announcements that they've spotted a suspect hiding in a tree in Haringey.
It was only when we arrived at the park that we realised the oddness of what we'd done - we'd come to see a celebrity helicopter from Twitter. That seems like a totally new media experience. Something you couldn't have imagined a few years ago.
I was sitting in a cafe on Sunday morning, staring at my Kindle, rather depressed by the number of long and important books queued up and unread on my screen. Lots of things I should read, nothing I really wanted to. And then - ping! - a new novel that I'd pre-ordered a few weeks ago got released and just turned up: a big, fat sci-fi novel that I ploughed into straight away.
This can happen anywhere in the world, wirelessly, magically, over the air. It's another of those media experiences we take for granted, but which should still be utterly thrilling.
We were staring at the telly on Sunday evening, too exhausted to do anything else after a busy day, but uninspired by the prospect of more Downton. A friend on Twitter suggested Broken Arrow. He thought my son would appreciate the imaginative swearing and helicopter explosions. Two minutes later - and a few clicks via the Apple TV - and we were watching it.
That one at least was reasonably predictable - in fact, media futurists have been banging on about it for years.
But when it happens, and it's normal, almost banal, it feels interestingly different.
And then there's this. This thing I'm writing. Well, not writing. I'm dictating this to my phone as I walk around the park. When I get home, there will be a text file waiting in my Dropbox. It won't be 100 per cent what I dictated, but it won't be a bad start.
Maybe I'm just in a starry-eyed mood, but this is all a bit extraordinary, isn't it? No wonder it's hard for us all to keep up - new media experiences just seem to drop out of the sky. Like celebrity helicopters on Twitter.