Steve Ballmer has been at it again.

On stage at a company event in Seattle, the Microsoft chief executive grabbed an iPhone and pretended to stamp on it to a chorus of boos.

The incident apparently happened after he spotted an employee taking a picture of him using an Apple handset. After his mock attack, he left the iPhone on the floor and went about his business - but apparently made a few more jibes later in the presentation.

The episode appears to be the result of exuberance, a dose of Incredible Hulk and partly a rallying cry for the troops who are under fire and outsmarted by competitors.

Of course, the Microsoft chief - who seems to slurp constantly from some unknown, unending energy source - has a history of bizarre on-stage appearances. Who can forget the soul-piercing screams of the dance monkey boy, or the sweat-laden, inner turmoil expressed during his 'developers, developers, developers' chant?

Whatever it was - venting his frustration or boosting staff morale - there is a certain poignant note to his reaction to Apple's device, particularly given how he laughed at the iPhone soon after it was announced.

"Five hundreds dollars?" he chuckled. "That is the most expensive phone in the world and it doesn't appeal to business customers because it doesn't have a keyboard - which makes it not a very good email machine. It may sell very well or not [but] I like our strategy, I like it a lot."

Everybody loves a bit of hyperbole, and Ballmer certainly deals in it. But for all the fun and games, however, there is a deeper issue here. Does it make sense to mock his competitors, rather than learn from them?

There is, of course, a genuine reason for using your own products - the theory charmingly known as "eating your own dog food", something in part pioneered by Microsoft. But there's a counterpoint to that, Not Invented Here syndrome - where companies wilfully ignore things from outside their own walls. Sometimes there's a fine line between the two.

For all the fun and games, perhaps Ballmer's latest moment of madness isn't just a piece of entertaining smackdown from a man who often appears to get his motivational tips from watching pro wrestling videos.