Back in the days before the term "Web 2.0" was coined, I started making note of when an emerging technology came into use by the early adopters and how many years it would take to reach the mainstream croud at NECC. This year's data point is Twitter. Sadly, the lag isn't getting any shorter: It's still about three years.

Blogs

Emerged 2002. Mainstreamed 2006.

In 2003, Clarity hosted an informal session of early adopters who were writing "weblogs" about education. (That same year was the first unofficial NECC blog pictured at right.) Each year thereafter saw greater acceptance and understanding of blogging, but it wasn't until the EduBlogger Meetup in 2006 that blogging was clearly mainstream. Evidence of this was in the NECC 2006 program: that year featured more than 30 sessions about blogging. And in the following year was the "first" EduBloggerCon.
 

Desktop Open Source Software

Emerged 1999 Mainstreamed 2005 

While several open source software tools have been common place for decades on the back end (for example DNS, email and Web services), the desktop environment was mostly a dormant frontier until the K12 Linux Terminal Server Project (LTSP) introduced the possibilities in 1999. Awareness and adoption finally accelerated in 2005 with the launch of OpenOffice 2.0 as an alternative to Microsoft Office. Today, it's not uncommon for older machines that can't run Windows XP or newer to run K12 LTSP instead.
 

Moodle

Emerged 2002. Mainstreamed 2004.

Tired of the poor quality of learning management tools, Martin Dougiamas created software for creating a Modular Object-Oriented Dynamic Learning Environment, more commonly known as Moodle. Written for educators, it quickly became recognized as a suitable platform for online learning. Due to a lack of familiarity with open source software, it remained in the shadow of the commercial tools Blackboard and WebCT, until open source software itself became mainstream. Interestingly, K12 education (unlike higher ed) is mostly unaware of alternative open source learning management systems, such as Sakai.
 

Wikis

Emerged 2003. Mainstreamed 2007.

The idea of a wiki caught on quickly in education, but then seemed to hit a wall. What delayed it's adoption wasn't awareness, but difficulty in setting one up. Luckily, wikispaces came into being in 2005 making it incredibly easy to setup and use a wiki. Their work to create a custom solution tailored for education in 2006 is what catalyzed its widespread use. Even so, the potential of wikis remains somewhat underutilized, partially because of the high demand they require for care and feeding. Advanced formatting, like the work we did in 2005 with ISTE's SIG-TC, is still very rare to see in wikis today (nearly five years later).
 

Cell Phones

Emerged 2005. Mainstream ????

One promising technology for education that has yet to reach the mainstream, (though it's trying very hard to get there), are cell phones. They bridge digital divides (cell phone ownership and use is higher among lower SES populations – according to research) and enable informal learning to occur beyond the school walls. When compared to 1:1 laptop initatives, it's more cost effective, requires less support (since nearly everyone already knows how to use their cell phone), and the investment in equipment is magnitudes less (since nearly everyone already has one).