Jessica Alba (left), Padma Lakshmi [Images] (centre) and Alicia Keys [Images] (right) are asking Americans to save their pennies to save a child's life.

'I am doing a hundred things,' says Lakshmi, a chef, cookbook writer, model and occasional actor. 'But I think I find a few things to be as passionate about as doing something for children.'

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She is among half-a-dozen celebrities involved in the Good Cents Initiative -- a campaign by the AIDS charity Keep a Child Alive. Model Iman also appears in the series of ads, which appear in glossy magazines throughout America.

The women, most of them dressed in black, pose against the headline: 'A dollar saves a life.'

While the 26-year-old Alba, who is smiling in a drizzle of pennies, represents a younger generation, Lakshmi, 37, and Iman, David Bowie's 52-year-old wife, appeal to an older generation.

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Lakshmi -- the former wife of author Salman Rushdie -- is seen kneeling in front of an oversized US penny.

'As celebrities we have unique opportunities to bring about a change and make an impact,' Lakshmi says. 'I think it is a great challenge and it also gives one a lot of satisfaction.'