A study on how to relieve jetlag in hamsters won one of the prizes

Other winners included work on treating hamster jetlag with impotency drugs, extracting vanilla from cow dung, and the side-effects of sword swallowing.

The awards, founded in 1991, mark achievements that "first make people laugh, and then make them think".

The prize ceremony took place at Harvard University, US.

Genuine Nobel Laureates handed out the much-coveted awards to the winners, who took away no cash, but instead received a hand-made prize, a certificate, and, of course, the glory of such an illustrious win.

Sword effects

Dan Meyer, executive director of Sword Swallowing Association International and an author of the British Medical Journal paper Sword Swallowing and its Side-Effects, said: "I was surprised and extremely honoured when I found out I was not only nominated for an Ig Nobel prize but that I had won it. I couldn't believe it."

He told the BBC News website that the study revealed that when professional sword swallowers ingested a single sword very carefully, it did not do much harm, but swallowing many swords, strangely shaped blades, or being distracted when swallowing, could cause injury.

The findings also suggested that sword swallowers should not swallow swords if they already had a sore throat, he said.

Unfortunately, said the organisers, nobody from the US military who carried out the research on chemicals that could prompt homosexual dalliances amongst rival troops (a research project called Harassing, Annoying and "Bad Guy" Identifying Chemicals) attended the ceremony because the study's authors could not be tracked down.

Real research

The Ig Nobel Prizes were created by the Annals of Improbable Research (AIR), a science magazine.

The Ig Nobels celebrate the unusual side of research

The awards, now in their 17th year, are intended to "celebrate the unusual, honour the imaginative - and spur people's interest in science, medicine and technology".

Marc Abrahams, the editor of AIR, told the BBC News website: "When I became the editor of a science magazine, suddenly I was meeting all kinds of people who had done things that were hard to describe, and for the most part, nobody had ever heard of.

"For some of them, it seemed a great shame that nobody would give them any kind of recognition, and that was what really led to the birth of the Ig Nobels."

Like their more sober counterpart, the Nobel Prizes, the Ig Nobels are split into several categories and all research is real and published.

2007 Ig Nobel Winners

Medicine - Brian Witcombe, of Gloucestershire Royal NHS Foundation Trust, UK, and Dan Meyer for their probing work on the health consequences of swallowing a sword.

Physics - A US-Chile team who ironed out the problem of how sheets become wrinkled.

Biology - Dr Johanna van Bronswijk of the Netherlands for carrying out a creepy crawly census of all of the mites, insects, spiders, ferns and fungi that share our beds.

Chemistry - Mayu Yamamoto, from Japan, for developing a method to extract vanilla fragrance and flavouring from cow dung.

Linguistics - A University of Barcelona team for showing that rats are unable to tell the difference between a person speaking Japanese backwards and somebody speaking Dutch backwards.

Literature - Glenda Browne of Blue Mountains, Australia, for her study of the word "the", and how it can flummox those trying to put things into alphabetical order.

Peace - The US Air Force Wright Laboratory for instigating research and development on a chemical weapon that would provoke widespread homosexual behaviour among enemy troops.

Nutrition - Brian Wansink of Cornell University for investigating the limits of human appetite by feeding volunteers a self-refilling, "bottomless" bowl of soup.

Economics - Kuo Cheng Hsieh of Taiwan for patenting a device that can catch bank robbers by dropping a net over them.

Aviation - A National University of Quilmes, Argentina, team for discovering that impotency drugs can help hamsters to recover from jet lag.