Tropical Storm Zeta formed in the open Atlantic Ocean.
Elton John and his partner David Furnish registered their civil partnership at Windsor Town Hall on the first day civil partnerships could legally be performed in England.
Cristina Fernandez was sworn in as Argentina's first elected female president.
Brokeback Mountain film was released, directed by Ang Lee, and based on the story by Annie Proulx.
The first partial facial transplant was given to Isabelle Dinoire in France after a dog attacked her.
Angela Merkel became the first female Chancellor of Germany.
The European Space Agency launched the Venus Express, the first European spacecraft to reach Venus.
RedOctane released Guitar Hero for PlayStation 2 in North America.
The fourth movie of J.K. Rowling's novel series, 'Harry Potter and the Goblet of Fire,' premiered in Leicester Square, London, UK.
Riots broke out in Paris, France, after two Muslim teenagers were electrocuted trying to evade police.
Sid Meier's Civilization IV was made available to PC players in North America.
Iraqi President Saddam Hussein was tried for his crimes against humanity.
Stephenie Meyer's vampire novel 'Twilight' was published.
The pilot episode of 'Supernatural,' created by Eric Kripke, aired on The WB Television Network.
Russia and China began their first-ever joint military exercise.
A mega blackout happened on Java and Bali islands in Indonesia, affecting around 100 million people.
The Provisional Irish Republican Army (IRA) called for an end to 36 years of bloody conflict with the UK.
NASA decided to suspend space shuttle flights after analyzing the launch of mission STS-114.
American romantic-comedy Wedding Crashers premiered.
The London bombings took place.
David Tennant was seen for the first time on Doctor Who.
France voted against ratifying the proposed Constitution of the European Union.
An assassination attempt was made on President George W. Bush.
The Huffington Post was launched, founded by Arianna Huffington, Andrew Breitbart, Kenneth Lerer, and Jonah Peretti.
The Airbus A380 passenger airliner successfully underwent its maiden flight.
Romania and Bulgaria signed the European Union's Treaty of Accession, the last step to joining the Union.
The first video was uploaded to YouTube.
Cardinal Joseph Ratzinger was elected as Pope under the name Pope Benedict XVI.
NASA launched a spacecraft to rendezvous with a small communication satellite.
NASA celebrated April Fool's Day by telling the world that they found water on Mars.
ABC debuted the first season of 'Grey's Anatomy.'
The Office, created by Ricky Gervais in the UK, aired its first US season on NBC.
The first God of War game was released for the PlayStation 2 to the North American market.
Steve Fossett completed the first around the world airplane solo non-stop journey.
Reality documentary The Apprentice (UK) premiered with businessman Lord Alan Sugar as the leading judge.
YouTube was founded & the domain name youtube.com was activated.
The Animated sitcom 'American Dad' aired for the first time on FOX.
The Civil Marriage Act was introduced, making same-sex marriage legal in Canada.
Spilled coconut water caused a stampede that killed more than 258 people in India.
France revealed the world's largest commercial aircraft, nicknamed the superjumbo.
NASA's Deep Impact space probe launched from the Cape Canaveral Air Force Station in Florida.
