If there was any doubt micro-blogging and social networking site Twitter has arrived as a true online force, it will dissappear tomorrow when an estimated 300 people descend upon Mountain View, Calif., for 140: The Twitter Conference.

Over two days at the Computer History Museum, developers, bloggers, the entrepreneurial and PR-types will attend seminars on how to use Twitter to promote businesses.

It’s being organized by Parnassus Group, a consulting firm that helps companies track and manage what’s being said about them on social media —Twitter, Facebook, blogs, message boards and everywhere on the web.

The Twitter Conference may seem too miniscule topic to base an entire conference around — especially at $395 US a head — but Steve Broback, head of Parnassus, thinks otherwise.

“(Attendees) are Twitter enthusiasts, and want to commune with other early adopters of what is emerging as a pivotal web-based ecosystem,” he says — and the way he puts it, it’s a broad audience.

In such a connected age, it would be remiss for a company not to represent itself online, especially on Twitter, a format that lends itself to honest, direct conversations — the 21st century version of word-of-mouth.

“As individuals and consumers, we have a lot of power today that we never had in the past. We can share our impressions on anything, just about anywhere online,” says Warren Sukernek, director of content marketing for Radian6, a Fredericton, N.B.-based company similar to Parnassus Group. “The really impactful ones (such as) a simple blog post can spread virally like wildfire.”

That’s why it’s imperative for companies to maintain a strong Twitter presence, build relationships and respond to what’s being said about them, he adds.

Companies successful on Twitter bear similarities. For example, JetBlue Airways (@jetblue) reports delays, announces fare sales and answers questions, while U.S. Internet provider Comcast (@comcastcares) has been a case study in amending its poor reputation. In 2006, a Comcast technician who fell asleep on a customer’s couch while on hold with his own company support line became a YouTube embarrassment, but the company now works to prove they really do care, resolving any problem instantly through Twitter that might otherwise require being put on hold for hours. Both identify employees manning the Twitter account, to build a sense of personality to the conversation.

Sukernek uses the much-grumbled-about Rogers as a hypothetical example: “If you were to send a question to Rogers, and they didn’t respond, your impression is that they failed, they stink. Whereas on the other hand, if you said something to them … and they responded within 10 seconds, and it was relevant, you’d think, ‘Wow, that’s cool that there’s a person there.’ Being on Twitter can humanize a company and a brand.”

Ignoring customers won’t work; that’s clear. Neither will shamelessly shilling its product, adds Broback.

In a lot of ways, social networking sites really are what they’re called. The time-old rules of traditional networking still stand, says Sukernek: Be friendly, helpful and ready to reciprocate. “Networking has existed forever and all the strong benefits of networking don’t change today.”