So if you've read Gladwell's Tipping Point, you'll appreciate this one.

I was taking my daughter down to the local outdoor playground on Sunday, and the car park was unusually full. As in, completely. People were even parking up on the grass, and in no-parking zones. Cars all over the place. "Feck!", says I. "Look, the Park!", says herself, with no room for excuses.

Except, the local credit union car park, right next door, is empty. I'd say it's the great big scary "we will clamp you and your children unto the seventh generation" sign. So nobody has dared disgrace this tarmac. They've parked illegally everywhere else, but not in this car park.

Anyway, I have no time for this, so I just park there anyway. You can see the car from the playground and I'm ready to storm over and have it out with any clamping truck that comes along. Plus, you can see them coming along the main road so there'll be plenty of warning.

An hour later we head back to the car. The entire car park with the scary signs is now full. Looks like I've started something. As soon as one car did it, all the rest followed. Seems like the tipping point is one car.

I suppose it makes sense too – if there are loads of illegally parked cars, the clampers will take longer to get to yours. But the main reason is probably the old "everybody's doing it so it must be OK" line. So my tip for the week is, park it, and they will follow. Want to make use of a reserved car park? Just park and you'll soon have a bunch of followers to take the heat…