The McCain 'Twitterview': has Twitter jumped the shark?

That "Twitterview" was a little weird.

Watching questions from George Stephanopoulos (@GStephanopoulos) and answers from Sen. John McCain (@SenJohnMcCain) bounce back and forth felt like watching a tennis match on delay. But it took Twitter somewhere it hadn't been before, and brought users an instant interview with a major newsmaker in a format that only it could manage.

Now that everyone from Martha Stewart to your crazy uncle is using the microblogging site, has its time as a tech darling come and gone?

Surprisingly, the answer appears to be a resounding no.

Despite an influx of what would seem to be the least likely members to jump on the cutting-edge tech bandwagon, the site is flourishing. Two years after its debut, it's still "out-and-out dominating" the South by Southwest Interactive festival, the place where tech trends are born.

Last week on his Late Night TV show, Jimmy Fallon tapped Diggnation hosts Alex Albrecht and Kevin Rose to help him turn an ordinary audience member into a Twitter celebrity. And champion cyclist Lance Armstrong famously got out the word about his stolen bike – and got it returned – by alerting his 300,000-plus Twitter followers.

But besides the fun of social networking stunts or the thrill of following your favorite celebrity's updates – showing up at the diner where basketball star Shaquille O'Neill is twittering is fun, for sure – Twitter is emerging as a useful tool.

On the most basic level, it's good for keeping friends informed of what you're up to and sharing new discoveries. Then there's promoting your work through tweets and links, and expanding your personal network of contacts by tweeting about conferences or events you're attending.

But what about as a live search engine? Why search Google for a news story that's hours or even days-old, when there are tweets coming across every few seconds about a major event like the plane that made an emergency landing in the Hudson River (a story that, incidentally, was first reported on Twitter)?

The site is useful as a live-blogging platform, too. Today's Apple press conference on updates to the iPhone's software was covered on Twitter with live updates from Macworld,  providing small bits of information quickly, and to a wide audience, before a story could be written.

The Guardian even reports that a job search site has sprung up that scrapes data from millions of tweets to gather information about openings, presenting a possible revenue model for the site.

So has Twitter peaked? On the contrary – the message now is: Watch out, Twitter is still growing.