At last year's architectural biennale in Venice the American pavilion hosted a display of green urban guerrilla agitprop. Groups of environmentalists in US cities play witty pranks, such as digging up parts of underused car parks overnight and planting them with vegetables, or turning redundant phone booths into plant displays.
Perhaps that is the kind of infrastructure investment Vince Cable wants to see more of.
US cities are also seeing a revival of guerrilla gastronomy. On the way to a meeting in the Flatiron district the other day, I bumped into a cheese factory on the corner of 20th Street and Broadway, just round the corner from Teddy Roosevelt's birthplace.
This branch of Beecher's wasn't there when Teddy got the munchies: the equipment is gleaming stainless steel, on public display behind a glass wall in what is otherwise a conventional deli.
The original Beecher's is in Pike Place, Seattle, which was the first home of Starbucks, too, so if it follows the same trajectory as its neighbour you might find a cheese factory turning up in your local bookstore or library quite soon.
But for the moment they are feeding the hungry of lower Manhattan with cheeses called Jack, Original Flatiron, Dutch Hollow Dulcet and an off-putting confection called No Woman, a mixture of curds and Jamaican jerk spices. I left that one in the vat, not wanting to provoke the Border Agency boys at Heathrow unduly.
Over the bridge in Brooklyn, they don't do cheese, but in Williamsburg there's a chocolate factory worthy of Willy Wonka. It's run by the extravagantly bearded Mast brothers, who look like extras from the Hobbit film.
Once again, the manufacturing is done in plain sight, in the back of a shop in an old warehouse.
In Britain, we have already been told to take an interest in the percentage of cocoa solids in our Green & Black's, but it turns out chocolate is far more complicated than that. Even to buy a single bar at Mast's to go with your decaf soy latte you need to know the difference between a blend and a single estate slab.
I take the latter to be the single malt of the chocolate world - the price differential would suggest as much.
Having surmounted that hurdle, you need to navigate the complexity of the flavour choice. I hesitated between Almonds and Sea Salt, and Vanilla and Smoke. The latter won it in the end. I was intrigued by the combination of smoked cacao from Papua New Guinea and bourbon vanilla bean from Madagascar.
Then when I discovered they had been 'slowly stone-ground over the course of days and then aged', I was ready to put down my $10 for something the size of a standard Dairy Milk bar.
I doubt that milk-based niche manufacturing is going to be the answer to mass urban unemployment in the EU, but value-added agriculture is an increasingly lively sector.
I used to walk my dog around a small industrial estate in Shepherd's Bush. She was particularly intrigued by the smells surrounding one of the units, the original location of Innocent smoothies.
That enterprise is now owned by Coca-Cola, but down in Dorset we are surrounded by dynamic small enterprises making a buck out of potato crisps priced like truffle flakes, prettily packaged tea and coffee vacuum-packed by Dorset hands, apple brandy (we aren't so keen on that as we suspect it comes across the border from Somerset under cover of darkness) and even chilli-infused chocolate, No Woman style.
Global warming has also worked its magic and delivered us a flourishing local vineyard. We took a bottle of Furleigh Estate champagne (I know they can't call it that because of some tedious European Directive) to Paris recently to amaze our French friends, and duly amazed they were.
Initially, there was a hint of the Dr Johnson attitude to a woman preaching - 'like a dog's walking on his hind legs.
It is not done well; but you are surprised to find it done at all'. But the fair-minded Parisians (an oxymoron, I know) were obliged to admit that it could have been a respectable small marque from the borders of Champagne proper.
I think I won't try them on the Dorset Coast white or the Tyrannosaurus Red, a joke that doesn't quite translate.
Oddly, the estate is run by a former colleague at the Financial Services Authority, which just goes to show that something useful can emerge from financial regulation. Something long- lasting, too: the Furleigh Estate looks to be there for the long haul, while the FSA itself died at the end of March. I wasn't invited to the wake.
There is wine, too, on the Scilly Isles. In my Airport Commission's endless search for an uncontroversial location for a new runway, I called in on Newquay airport on my way there the other day. Before a Stop Newquay Expansion group gears up, I should point out that I was in Newquay by accident, as Land's End airport was closed owing to flooding.
I noticed that there was quite a bit of spare capacity on what used to be RAF St Mawgan. But the surface connectivity, as we call it, left a bit to be desired.
We were driven back to Penzance to catch the train that connects with the bus from Land's End, which is a circuitous way of getting back to civilisation. The upshot was that I got a train two hours late and had to pay the whole fare again as my reservation was invalid.
The guard was uninterested in the failed airline connection. Then the train turned into a bus, so it took 11 hours to get from Newquay to Paddington. It was a good job there was No Woman at home when I finally made it.