Perhaps the most profound thing I overheard at this year’s SXSW Interactive festival didn’t come from a panelist, or an organized talk, but from Diane Sawyer on Good Morning America one morning while getting ready in my hotel room. I had just zipped up my laptop bag, checked the mirror one last time, and was about to turn off the tube when Diane began reading “tweets” that they were getting from viewers of the show’s current topic of discussion. I lowered the remote, and stared at the TV. Did she really just say “tweets?”

If you aren’t familiar, Twitter is a micro-blogging site that began as a place where users create a personal page, and continually answer the question: “What are you doing right now?”

Beyond its practical purpose as a site that allows your friends and/or Twitter followers to know what you’re up to at any given time, it has really become a place to engage in real-time dialogue with your followers. But it doesn’t stop there.

Groups of people are also connecting on topics, and providing thought and feedback to the entire Twitter community by marking posts with keywords. I would venture to guess that 99% of the SXSW Interactive audience uses Twitter, and during the conference, it was an incredible tool to keep an attentive ear leaned toward the conference as a whole, so that you never felt like you were missing out on something important.

I think its value as a tool to open a real-time running dialogue with a business’s customers is invaluable. Obviously, since Diane Sawyer is getting tweets on GMA and working responses into the programming! It’s probably safe to say that Twitter is going to become just as mainstream as email, and will give consumers and companies new avenues to interface.

If you’re interested in more information on Twitter, check out the ultimate guide for everything Twitter.