In a few months, AOL Instant Messenger will go the way of such tech touchstones as AltaVista and Netscape. It was 20 years ago that "AIM" went online. It quickly exploded in popularity, peaked and then slowly succumbed to competitors.For many of us, AIM conjures up memories of dial-up modems, the sound of a "handshake" and the phrase "You've Got Mail.""AIM tapped into new digital technologies and ignited a cultural shift, but the way in which we communicate with each other has profoundly changed," says Michael Albers, vice president of communications product at Oath Inc., a subsidiary of Verizon Communications that brought AOL and Yahoo together into a single unit earlier this year.On Twitter, a social media platform that in no small way contributed to AIM's demise, people seemed a bit nostalgic but not terribly surprised."You likely remember the CD, your first screenname, your carefully curated away messages, and how you organized your buddy lists," Albers says. "In the late 1990's, the world had never seen anything like it. And it captivated all of us."In fact, by 2001, AIM had captivated about 100 million of us worldwide, but as Techcrunch.com writes: