Robert Thompson, a professor of media and popular culture at Syracuse University in New York, agrees that "We behave in very different ways each hour of the day in 2009 than in 1999."
He and others believe the past decade may be remembered as the time when major technological and social changes went mainstream and changed the way we live.
"I think we're going to be referring to this as the digital age," he says. "When you think of it, YouTube falls right in the middle of this decade. ... The whole notion of texting and Twitter and Facebook has all been in the confines of this decade. And already, as we get to the end of this decade, we're starting to see that settling down."
As the new decade starts, "the actual opera is about to begin," he adds. "I think the actual preparatory stage has reached a sort of, maybe not closure, but ... we have a sense of what the landscape looks like. And most people have come to grips with what this future looks like. There are very few people who still say, 'Send me a letter, I don't understand e-mail.'"
Thompson argues that other decade threads remain open. For instance, the consequences the 2000 election and 9/11 -- such as the wars in Iraq, in Afghanistan and on terror -- may continue for years or decades to come. And the recession blues continue through high unemployment.
He sees tighter focus around the technology story in a decade that began with the Y2K scare.
"This decade started in its very first second with the fear that planes were going to fall from the skies ... our ATMs wouldn't work, the whole grid would go down," Thompson says. "The first decade of this century ends with us having made a thousand more contracts with that devil."
"So much of my life, professionally and personally, goes through that Internet connection, and when it goes away it's very traumatizing," Thompson says. "That doesn't mean I think we should go back to the days of blacksmithing. But it's true: You lose that one connection, and its curtains."
Now, Thompson says, Internet personalities not only have an online platform, but a small percentage routinely pepper the traditional-media ranks of TV's morning show talking heads.
Sigl admits he and other bloggers wouldn't have been heard a decade ago.
"I think this past 10 years was the most significant decade in terms of social change ... since the 1960s," Sigl says.
Sigl also would have more trouble assembling his project years ago. But the same access to information that can settle any bar argument instantly with an iPhone connection allows Sigl to do most of his blog research "from my living room."
Add in phenomena like Britney Spears, the octomom, the celebrity blogger Perez Hilton and reality TV, and Sigl sees a second running theme perhaps bigger than technology.
"Everyone's a celebrity," he says. "I think the appeal of social networking is not just reaching out and connecting with your friends. ... You can read about these things as if you're in a magazine or something. ... It's narcissism of a kind that really has exploded this decade."
It's the "all-about-me decade," he says.
Others aren't so sure.
"I would say the all-about-me decade has been happening for a whole lot of decades," Thompson says, citing "Oprah," the 1970s "me generation" and even Sigmund Freud's "talking cure."