Nobel Prize (search) week is upon us, but to find out who the front-runners are, the best you can do is ask the bookies.

Like the Oscars (search), the choosing of scientists, writers and peacemakers for the world's most coveted award is a process shrouded in secrecy, leaking nothing until the envelopes are opened, starting Monday with the award for medicine.

"This is a very desirable award and that also makes it very sensitive," said Jonas Forare, a spokesman for the Royal Swedish Academy of Sciences (search), which selects the winners in chemistry, physics and economics. "It is not good if names are circulating in the air."

For the Peace Prize, to be announced in Oslo, Norway, on Friday, Australian betting agency Centrebet's favorite at 4-1 is former Finnish President Martti Ahtisaari (search), who brokered peace efforts in the Balkans and Namibia.

Nobel watchers cannot but grasp at straws. This year marks the 60th anniversary of the bombing of Hiroshima and Nagasaki, so Sen. Richard Lugar and former Sen. Sam Nunn were fetching odds of 6.5-1 for their program to dismantle Cold War-era nuclear arsenals.

But rock musicians Bono (search) and Bob Geldof (search), who campaign to ease Third World poverty, also were doing well, having gone from 66-1 to 7-1.

For literature, British-based Ladbrokes gave its shortest odds to Syrian poet Ali Ahmad Said, known as Adonis; Korean poet Ko Un; American novelist Joyce Carol Oates; and Swedish poet Tomas Transtromer.

Other perennials were American Philip Roth and Peruvian-born Mario Vargas Llosa. Europeans have won the literature prize in nine of the past 10 years, so the experts think the Swedish Academy may look outside Europe this year.

Should any of them be runners-up, we won't know until 2055. The rules keep the candidates' lists secret for 50 years. To find out who were nominees from 50 or more years ago was a laborious bureaucratic process, but lately the Nobel Foundation has begun listing some at http://www.nobelprize.org.

The peace nominations reveal some of the embarrassments the Nobel committee has managed to avoid: Adolf Hitler, nominated in 1939 by a Swedish legislator and withdrawn the same year; Soviet dictator Josef Stalin, nominated in 1945 by a Norwegian former foreign minister and in 1948 by a Czech professor; Italian dictator Benito Mussolini, who got two nominations in 1935, by a French law professor and a German college law faculty.

Since the first prizes were awarded in 1901, some winners have famously turned them down: The French philosopher Jean-Paul Sartre refused the literature prize in 1964 and North Vietnam's Le Duc Tho, honored jointly with U.S. Secretary of State Henry Kissinger (search) for negotiating the Vietnam peace accords, turned down the peace prize in 1973.

Boris Pasternak, author of "Dr. Zhivago," and Alexander Solzhenitsyn ("The Gulag Archipelago"), were so reviled by their Soviet government for winning the 1958 and 1970 literature prizes that they refused to travel to Stockholm for their awards, fearing they would be banned from returning. Last year's literature winner, Elfriede Jelinek of Austria, accepted the prize but skipped the award ceremony and banquet, citing her "social phobia."

There are few guidelines for deciding who wins. Alfred Nobel, the Swedish inventor of dynamite who founded the prizes, left only vague instructions in his will 110 years ago: scientific prizes for those "have made the most important discovery," literary prizes for "the most outstanding work in an ideal direction," and the peace prize to someone who worked for "fraternity between nations, for the abolition or reduction of standing armies and for the holding and promotion of peace congresses."

The prizes, denominated in Swedish kronor, have multiplied 66-fold since 1901 and are now worth $1.3 million each.

The Nobel Memorial Prize in economic sciences was established by the Swedish Central Bank in 1968 — the only award not established in Nobel's will.

The first laureates included Wilhelm Conrad Roentgen for his discovery of X-rays, and Jean Henry Dunant, founder of the International Committee of the Red Cross.

Of the 713 Nobel laureates, 33 have been women. The youngest, Englishman Lawrence Bragg, won the 1915 physics prize at age 25. The oldest was American Raymond Davis Jr., the 2002 physics laureate at 87.

1906 peace laureate Theodore Roosevelt (search) was the first American to win a Nobel, and he and Woodrow Wilson (search) (1919) are the only U.S. presidents to win the peace prize while in office. Former President Jimmy Carter (search) won it in 2002.

The Nobel Prizes are presented Dec. 10, the anniversary of Nobel's death. The peace prize is awarded in Oslo, and the other Nobel prizes are presented in the Swedish capital.