Pupils in Hampshire primary and secondary schools have been challenged to come up with ideas for inventions to help raise funds for Naomi House, the children's hospice at Sutton Scotney, near Winchester.

The challenge, from the Wallace and Gromit's Children's Foundation, is part of "Wrong Trousers Day", sponsored by pharmaceutical giant, GlaxoSmithKline, to raise funds for children in hospitals and hospices across the UK.

Children aged four to 18 are being asked to come up with an invention and show their research, design ideas and proposals for manufacturing and marketing.

The ingenious gadgets featured in the Wallace and Gromit films and in the recent Cracking Contraptions series have delighted audiences worldwide and it is hoped that they will inspire children to rise to the challenge to create the UK's most original invention.

The competition has been designed to match key criteria in the national science curriculum, encouraging young people to think creatively and solve problems.

A panel of judges, including Trevor Baylis, Sir Richard Sykes and Professor Sir Harry Kroto, will select a winner, a runner-up and a special achievement award from each of five different age groups.

The winning inventors will be invited to a prizegiving ceremony in September. Prizes for the finalists, and the winning school, will be provided by Hewlett-Packard.

Commenting on the competition, Hugh Thompson, fund-raising manager at Naomi House, said: "We are absolutely thrilled that we have been chosen as one of the children's charities from across the country to benefit.

"With Wallace and Gromit's help, I am sure that a great deal of money will be raised and that a large number of schools will get involved, particularly in the Winchester area."

Wrong Trousers Day is on July 4th when youngsters will be encouraged to wear wacky trousers, pyjamas and shorts along with their normal schoolwear in return for a £1 donation to the Wallace and Gromit Children's Foundation.