Hardly anyone actually shoots themselves in the foot or literally gets egg on their face, so it was a real pleasure last week, in so many ways, to witness Jacqui Smith being hoist with her own petard.

A petard was, in the original French, an explosion of intestinal gas which, in turn, gave its name to a small bomb, such as the one that erupted across the papers last week, when the neighbours of her sister's house in Peckham, south London, came forward and told the press that she was only there a couple of days a week.

Because, in the small matter of whether she was right to pocket £116,000 of additional expenses by claiming that the back bedroom she rents off sister is her "main home", as opposed to the house she owns in her constituency in Redditch where her husband and children happen to live, this turns out to be critical testimony.

Standards Commissioner John Lyon twice turned down requests to investigate the matter. It was only when some neighbours, Dominic and Jessica Taplin, wrote to him and repeated the claims they made to a newspaper, that she is there rather less than the four nights a week that she claims, that he agreed to open an inquiry.

It's this that's the real beauty of the story. Residents on the online East Dulwich forum (East Dulwich being what you call Peckham if you happen to live there) declared themselves outraged at the behaviour of the neighbours, with words like "snitch", "curtain-twitchers", "grassers" and "narks" being bandied about (apparently "Dominic and Jessica Taplin represent all that's worst about the new smug arriviste elements of East Dulwich"). This is the world that Jacqui Smith has created. The only shame is that they didn't capture her on CCTV.

If you want to rat out your neighbours, allow the home secretary to enumerate the ways. Do you know someone who claims more from the state than they're entitled to? Who is "picking the pockets of law-abiding taxpayers"? Not politicians over-egging their allowances, obviously, but "benefit thieves". If so, call 0800 854 440 now. "We're closing in with hidden cameras. We're closing in with every means at our disposal."

Do they own more than one mobile phone? Then call 0800 789 321. "Terrorists need communication. They often collect and use many pay-as-you-go mobile phones, as well as swapping Sim cards and handsets."

No mobile phones? What about if they're "hanging around"? Or, as the Home Office-funded radio advertisement puts it: "How can you tell if they're a normal everyday person or a terrorist? The answer is that you don't have to. If you call the confidential Anti-Terrorist Hotline on 0800 789 321, the specialist officers you speak to will analyse the information. They'll decide if and how to follow it up. You don't have to be sure. If you suspect it, report it."

It's such a lovely turn of phrase, that. If you suspect it, report it. Don't wait for evidence. Or question your own prejudices. If someone's not a "normal everyday person" exactly like you, then they could well be a member of al-Qaida. What flawless logic that is. We're already described as "a surveillance state" by Privacy International, one in five of all CCTV cameras ever made are currently in Britain, and Smith is drawing up plans to intercept every phone call we make and every email we send. The Taplins weren't snitches - they were perfect citizens in her New Model Army. And while her critics invoke the analogy of the Stasi, a more accurate comparison would be with a suburb in Connecticut, circa 1961.

Because for all its period atmosphere with Kate Winslet in a little pill-box hat, Revolutionary Road, the film for which she may or may not win an Oscar tonight, feels a curiously contemporary affair. Not just for its critique of capitalism, the profound sense of emptiness that afflicts the characters despite, or maybe because of, their material comforts, but because of the hermetic vision of suburbia it offers: a conformity of living, of beliefs, aspirations and behaviour that is rigorously policed by family, friends and neighbours. If you suspect it, report it. And if you live by the sword, Jacqui, you must be prepared to die by it too.

If I had an allotment, I'd know my onions

Thrilling news from the National Trust. It's going to dig up the gardens of its stately homes and create 1,000 new allotments. Although, unless they're cunningly disguised as council estates, it occurs to me that there aren't all

that many stately homes where us garden-deprived city folk tend to gather, ie in cities.

Britain is a small country, with a shortage of land, but it's not as small as the Czech Republic, where almost every family has a "chata", or summer house. Most of them are no bigger or more fancy than a garden shed, located in colonies in forests and woods. Even during the dark days of communism, it gave the tower block dwellers somewhere to grow things, gather things and pickle things.

Here, a second home is where one shows off one's enormous wealth and interior decorating skills. Which is why it's truly great news that Garrington, the property-finding firm owned by "property expert" Phil Spencer, went into administration last week. Not for Phil, obviously, or the people who lost their jobs, but if it means that C4 axes Location, Location, Location, the most zeitgeistless programme on the telly, then so be it.

But back to me. I'm delighted to report that I'm 871 on my council's allotment list. In 2008, 18 plots came up, so it's just a matter of sitting out the next 48 years. It's good to have something to look forward to and, as long as I don't do something premature, like die, I'm sure that taking up heavy digging in my 80s will be most rewarding.

What shall I buy - a sandwich or an engagement ring?

To those who have long suspected that the "credit crunch" is to the marketing departments of 2009 what "environmentally friendly" was to those of 2008 - ie the death of all imagination and an expedient way to get rid of any old rubbish - comes the Marks & Spencer £18 engagement and wedding ring set. These are no ordinary wedding rings. They're Marks & Spencer wedding rings, "diamante encrusted", platinum-plated and made of that well-known precious metal, "tin alloy". In place of a hallmark, "the M&S logo features on the inside of the bands".

Now there are those who say diamonds are not forever, they're for demonstrating you're happy to wear an object that has been mined by poorly paid African labourers employed by a vast, multinational company famous for its monopolistic practices.

But even so. The idea that this is a "credit crunch" wedding ring, as opposed to an opportunistic press release attached to a cheapo bit of tat found lying around the stockroom floor, is the equivalent of those signs about not washing the towels in hotel bathrooms for the sake of the environment: ie a lie.

And a pointless one at that. Because, to paraphrase Blackadder, not even a niggard who used to be professor of niggardliness at Oxford University would buy an engagement ring for little more than the price of an M&S prawn sandwich: a comestible-to-jewellery price comparison, which those with longer memories may recall was what sank poor old Gerald Ratner.

So here, for Sir Stuart Rose, M&S chairman and the overseer of its worst Christmas trading for a decade, is the rest of Gerald Ratner's fateful quote: "We also do cutglass sherry decanters complete with six glasses on a silver-plated tray that your butler can serve you drinks on, all for £4.95. People say, 'How can you sell this for such a low price?' I say because it's total crap."

My Ickle pony

For want of £20,000, South Ayrshire Council has decided that Pets Corner animal sanctuary must go. Farewell then, Barnie the donkey and Ickle the Welsh pony, who "will probably be forced to go to a market, where most horses are sold for meat". Yes, well, after press like this, I doubt Ickle will become the latest victim of the credit crunch.