Dec.3, 2012  -- It was 20 years ago today that the first text message was sent. It was Dec. 3, 1992, and Neil Papworth, an engineer working in the UK, sent the world's first short message service or SMS. It read "Merry Christmas."

But while most are entering their prime at age 20, the text message might just be past its glory years.

The History -- In More Than 160 Characters

Papworth, however, was in his prime when he hit the send button on that first text. At the age of 22, Papworth was working for a company called Semea Group Telecoms, which had been working on a mobile messaging project for Vodafone, a European cellular carrier.

"It happened that day that Vodafone wanted to try sending a message to Richard Jarvis, one of the directors there, who was at a Christmas party. So we sat at the computer and typed him a message and then sent him the message 'Merry Christmas,'" Papworth told ABC News. "For me it was just another day's testing, it didn't seem to be anything big at the time."

But, of course, it turned into something very big -- at least once some of the consumer technology caught up. On that day in 1992, Papworth didn't send the first message with his thumbs on a mobile phone. He sent it from a big computer in one of Vodafone's offices to a Orbatel 901 mobile phone, which was the size of of today's office phones, Papworth explains.

(Papworth isn't the inventor of the text message; the origins of the idea date back to 1984 when Matti Makkonen, a Finnish engineer, was working with Nokia on mobile messaging.)

At that time, you could only receive messages on phones; you couldn't actually send messages from phones until a year or so later when phones from Nokia and others had the proper capabilities.

"Years went on and people were able to start to send text messages. It took quite a few years of it to take off," Papworth said. "But by the 10th anniversary it was fairly big by then."

The Rise and Start of the Fall

And it became even bigger than that. In 2010, the International Telecommunications Union reported that 200,000 text messages were sent every minute and 6.1 trillion texts were sent worldwide. In June 2012, the CTIA mobile trade group reported that 184.3 billion text messages were sent a month in the United States -- up from 28.9 billion a month in 2007.

But in 2012, there is building evidence that text messaging is past its peak as more and more people have smartphones and use e-mail, instant messaging, iMessage, and other mobile messaging services to communicate.

In November, the New York Times reported that in the third quarter of 2012 text messaging was down. According to a report by Chetan Sharma, a mobile analyst, cell owners sent 678 text messages a month, down from 696 a month the previous quarter. It's not a huge hit, but it falls in line with other reports that text message usage is dropping.

"Texting isn't evolving, therefore it's declining," Patrick Moorhead, principal analyst at Moor Insights & Strategy, told ABC News. "There are way too many alternatives like iMessage, BBM, Facebook chat and Google Chat that are cross-platform that texting is a backup now for sophisticated users. Texting is more reliable but is declining as a primary tool."

Other experts also point out that users still need to pay for text messaging, while some of the other services are free, with no cap on the number of messages.

"It comes down to cost -- carriers still charge extra for text messaging after all these years, even though it costs essentially nothing to operate. It's pure margin," Chris Ziegler, a mobile phone expert and senior editor at The Verge, told ABC News. "Alternatives like BBM, iMessage, WhatsApp, and traditional instant messaging services, like Google Talk and Microsoft Messenger, only require a data package, which any smartphone user already has anyway. A savvy subscriber can dispense of their text messaging plan altogether and rely on data alone."

Additionally, with more of those services and social networks like Twitter and Facebook, users are finding texting to lack the features of the others. Ironically, Twitter, which says 60 percent of its users access the service on mobile, was based on text messaging. Like SMS' 160-character limit, Twitter has a 140-character limit and was designed that way because of text message capabilities.

"Twitter was inspired by SMS and we continue to embrace this simple but ubiquitous technology. In fact, Twitter's 140-character limit was designed specifically to allow for any tweet to be read in its entirety whether you're using a rudimentary mobile phone, or a more sophisticated Internet enabled device," Twitter wrote on its blog back in 2010.

But while Papworth admits that texting is past its prime, he believes it will still be very relevant for years to come. While a growing part of the population owns smartphones, which allow you to instant message, email, or connect to social networks, cellphone use without those features is growing at a very fast rate in emerging markets like India or Africa.

"Those handsets can do text messaging, but not everything can use data," he said. "Yes, the data is showing that it is starting to decline, but it's not going to go away. There is a lot of use for it alongside all the data services."