A long, long time ago, cell phones were used for just one thing: making phone calls. They were bigger than a book (a bound book), heavier than a brick, and used primarily for emergencies.
Forty years later, cell phones are so much more. No longer novelties, they are an integral part of our lives and hold a world's worth of information.
Take a look back at the evolution of the cell phone over the years.
Here, Chris Brasher, co-founder of the London Marathon, talks on a cell phone during the 1985 foot race.
Brick phones, 1988
Franck Piccard of France talks on his mobile phone after the Mens Super G Salomon event at the 1988 Winter Olympic Games in Calgary, Canada. Piccard won the gold medal with a time of 1:39.66 minutes.
SUSAN FARLEY/AFP/Getty Images
Hey, Mom! I won!
Austria's Michael Tritscher and Italy's Alberto Tomba talk on cell phones as they await their awards on November 19, 1995, after the Men's World Cup Slalom in Beaver Creek, Colo. Tritscher finished in first, and Tomba in third.
TOSHIFUMI KITAMURA/AFP/Getty Images
Personal Handy-Phone System, 1997
Michiko Matsuo of Kyocera Corp. displays the company's new Personal Handy-Phone System (PHS) mobile phone known as the DataScope DS-110.
The DataScope had IBM's ChipCard computer and weighed 175 grams. It was capable of accessing computer networks, transferring data, and using a wireless modem by inserting it into a personal computer's PCMCIA type II slot.
Kyocera was introduced to the Japanese market in February 1997 with a street price of around 50,000 yen (US$406).
HENNY RAY ABRAMS/AFP/Getty Images
AT&T and TCI merge
Michael Armstrong (left), chairman and CEO of AT&T, holds up a new cellular telephone while describing a new AT&T phone service at a June 1998 press conference in New York. Also pictured is John Malone, chairman and CEO of Tele-Communications Inc. (TCI).
The two announced that AT&T and TCI would merge in a transaction valued at approximately $48 billion. The merged companies provided customers with unified telephone service, cable television, and Internet access.
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This is Castro speaking
Cuban President Fidel Castro talks on a cell phone before the second working session of the VIII Ibero American Summit at the Alfandega press center October 18, 1998, in Porto, Portugal.
TORSTEN BLACKWOOD/AFP/Getty Images
Call from the desert
Papunya Aborigine Denis Minor calls his brother in the Tanami Desert on a mobile phone at an indigenous settlement on the outskirts of Alice Springs in Central Australia in January of 1999.
Toru YAMANAKA/AFP/Getty Images
"Locatio," GPS and camera
In 1999, Seiko Epson Corporation in Toyko launched "Locatio," which combined the functions of a global positioning system (GPS), a mobile phone and a digital camera.
GSM phase 2+ and GSM Pro system, 1999
The R250 PRO dual-band phone was the first mobile phone to support both GSM phase 2+ technology and the GSM Pro system, which allowed users the then-unique opportunity to combine the advantages of GSM phones with Private Mobile Radio functionality.
R250 PRO was marketed as "the perfect working tool for outdoor communications in tough environments." Equipped with GORE TEX membranes and rubber gaskets, the phone had a sturdy magnesium frame and rubber molding.
STEPHEN SHAVER/AFP/Getty Images)
Growth in China
In Beijing, two women working for Nokia help promote the company's mobile phones at a shopping mall. In 1999, China had more than 23 million mobile telephone subscribers. In 2012, there were well more than 1 billion people subscribing to mobile phone services in China.
MARTIAL TREZZINI/AFP/Getty Images
Millennium Multimedia Phone IMT- 2000
Samsung Electronics debuts its revolutionary Millennium Multimedia Phone IMT-2000 at the opening of the Telecom 99 and Interactive 99 exhibition in Geneva on October 10, 1999.
TOSHIFUMI KITAMURA/AFP/Getty Images
A 'Net gain
Nigel Rundstrom, vice president of Nokia Mobile Communications Japan, shows off the company's new mobile phone, DoCoMo Nokia NM502i, in Tokyo on March 2, 2000.
The NM502i was capable of sending and receiving e-mails and had access to the Internet through NTT DoCoMo's iMODE service.
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The web, from anywhere
Rosalie Chong, marketing officer for Sony Personel IT, displays the CMD-Z18 at a press preview on August 1, 2000, in Hong Kong. The newest handset supported both WAP (wireless application protocol) and Web (.html standard) functions, enabling users to surf online from anywhere.
ROSLAN RAHMAN/AFP/Getty Images
Multimedia Messaging Service (MMS)
Nokia introduced its mobile phone 6610 with Multimedia Messaging Service (MMS) at the Nokia Connection 2002 in Singapore on June 17, 2002.
The Nokia 6610 GPRS mobile phone could send digital images, as well as text messages.
BORIS HORVAT/AFP/Getty Images
Nokia 3650 video mobile phone
On September 6, 2002, in Marseille, France, Juha Putkiranta, the Finnish vice president of Nokia Image Service showed off the new Nokia 3650 video mobile phone and the new 3510i mobile.
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Call from the end zone, 2003
Joe Horn of the New Orleans Saints makes a cell phone call from the end zone after scoring a touchdown against the New York Giants on December 14, 2003, at the Superdome in New Orleans, La.
BEHROUZ MEHRI/AFP/Getty Images
Old World meets new
Cell phone usage spread quickly throughout the world in the early 2000s -- often in developing countries, where the new technology contrasted with ancient history.
Here, an Iranian speaks on his mobile phone among the ruins of the ancient citadel in the southeastern Iranian city of Bam on December 28, 2003.
Sean Gallup/Getty Images
A 1.3 megapixel digital camera, 2004
The new Sony Ericsson S700 combined a mobile phone and 1.3 megapixel digital camera at the CeBIT technology trade fair March 18, 2004, in Hanover, Germany.
The S700 also contained a memory stick port for transferring photos to a computer.
A phone or a PC?
Today our mobile phones are like personal computers. When the iPhone debuted in 2007, there had never been anything like it. Our smartphones have become an indispensable parts of our lives.