David Baddiel turned up at my son's nursery school here this week. The place has an international reputation but Baddiel wasn't lobbying to enrol his kids. Nor was he trying to pitch the venture-capital and serial-entrepreneur parents dropping off their toddlerpreneurs. (It happens, though).

No, the Cambridge-educated comic was making a film about child development for Horizon. He was re-enacting one of the most famous experiments in child psychology, and one that speaks powerfully to the Valley's mindset these days.

Popularly known as the marshmallow experiment, it was first conducted here some 40 years ago. Pre-schoolers were offered a choice between getting one treat (a marshmallow, originally) now, or two more if they waited for 15 minutes. The researchers wanted to see if you could teach children to rein in their impulses. It turns out you can. But then they tracked the kids through school, university and beyond. They found that children who were better able to delay gratification at age four did much better in later life.

We haven't had to practise that here for a while. In the last boom, VC money flowed like free beer to anyone who asked. Companies with the lamest of ideas got instant funding.

How times change. Twitter competitor Pownce folded this week. That was a shock. Pownce was a hot play in the hottest of web 2.0 spaces.

A year ago Pownce would have been snapped up for tens of millions, but we're now back to a business climate favouring those who can wait for the extra marshmallow. If Baddiel's film shows how we can learn to do that, the moment it gets on YouTube he'll have the entrepreneur parents at my son's school glued to their screens.

* We've had rather too much crowing here about how Valley-born technologies were used to report the Mumbai terror attacks. Even before the raids were over, the self-congratulatory blog entries and tweets were overwhelming. I did first hear about the attacks via my Twitter feed. But then things went downhill. A lot of what people posted was self serving, wrong or just re-posts of what people had seen elsewhere. Filtering the deluge was a huge job.

* It's flu season, which means nice press for Google for its Flu Trends tool. This aggregates all US Google searches for information about flu to map its spread much faster than before. And it means Digg founder Kevin Rose can create a Twitter account for his cold. A textbook example of the current Valley obsession with tweets.