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With stars like Madonna proving that a person's choice in fitness, fashion and lifestyle (cough, plastic surgeon) can take decades off their appearance, should certain hairstyles still be considered inappropriate after a certain age?

Take Demi Moore, for example. Her (beautifully) long locks go against the notion that such looks are only fit for those under 40. And then there's Claudia Schiffer, who has been spotted recently sporting the sort of edgy, rock 'n roll-inspired 'do once reserved for rebellious 20-somethings. And who can forget Gwen Stefani's "Today Show" appearance? That updo sparked a surprising debate about whether such styles are avant-garde or childish.

What do you think? Is it time to update (or bin!) our "rules of hair"?