Can I ask you a question, yeh?

In the field of bait & switch fraud, and outright begging, I wonder if the practices of spiel and strategy are making a return. I haven't heard a good line in ages, or a convincing one in ever and I didn't hear either th'other weekend, but two in quick succession is one short of a trend, no? A journalist would wait for the third, but I haven't need of such principle.

Great Portland Street, Saturday afternoon, in the vicinity of Villandry. It's a wide empty road, and some breed of hatchback is moving down and across with the slow solitude of a vehicle that didn't just leave the lights. Inside is a balding man with eyes so large his spectacles can barely contain them, he hails me and asks me the way to Heathrow. He's keeping it simple, but as they say in football, it's a poor first touch.

Now he has my attention he gets to the point, peppered with interrogatives to create a sense of engagement: 'I am Italian... you know Giorgio Armani? I have... you know John Lewis? I work, I buy... I see you wear good clothes...' Which is the point at which the seams of his clumsy garment of schmutter-patter fully pull apart. I was wearing my thirty-yard coat that day - it convinces at three dozen paces, any closer and its chainstore provenance is evident. Even with his mouth full of suits and jackets and prices those big goggling eyes of his are softening with disappointment. Because I just can't help smiling, and not rhetorically or out of politeness and we both know the exchange is over.

Conduit Street around nine on a Sunday evening, all the retail has died down and gone home. If I'd a dog this is where I'd be taking it for its evening walk - down to the foot of Bond Street and then zigzagging home left and right at random. We're on the lozenge of pavement outside the Westbury. Well made up and turned out she is, mobile in hand, no betraying blisters about the lips. And the opening question this time, reasonable enough for the district is 'Do you speak English?'. Then the cadge is quite well framed and delivered, in tones of contemporary received pronunciation though a trifle hoarse, a mix of ditz and desperation and, gosh, not knowing where to start, but here's the problem...

'My colleague's gone home... I'm just a bit short... need a taxi. You mustn't think... I'm [with? from?] Saatchi and Saatchi... I'm just a bit... short...'

I know Chas and Mo like to ride their ponies hard [in their lingering spirit], but not normally on either sabbath mine or theirs, and the basic premise clanks like a cracked bell. But this is all irrelevant in any case, because I've only popped out for a stroll and so am holding no folding money whatsoever and can honestly tell her that I'm as short as can be.

Surely somewhere in academia there are studies on strategies for enhancing credibility and exploiting credulity in these circumstances. Because, cold, without reference to need or motive, it's fascinating. There's at least a full PhD's worth in there. Maybe when I retire I'll do that. And get a dog.