Blog. Twitter. Facebook. YouTube.
On his blog, Chris Brogan wrote:
The point is actually simple. Coming up with a one-size fits all strategy for dragging companies into social media is just goofy. [...]
It's not all about the conversation. It's not a matter of whether you get it or don't. Like all things, it's finding what works, building from a foundation, measuring progress, and adapting to new situations.

Brogan explores the necessity of social media from a corporate perspective. Should a company have a a blog? Be on Twitter? Or Facebook? Or YouTube? Or any other incarnations?
I tried Twitter and found the idea of posting the minutiae of my daily life inane. So it's not for me. But what about instant communication, the online water cooler, ultimate connectivity, all of these are used to describe why Twitter is successful even against harsh critics like myself. It can most certainly work for any given organization but I would first ask if you care enough to express that minutiae to the public and if that public cares enough to read it?
Are you on Facebook? Almost everyone I can think of would say yes. That might be enough said.
I love video as a medium to distribute information and to connect. YouTube simply happens to be the most popular way to do so at the moment -- bite-sized pieces of content streamed visually, quick and simple.
Blog to your heart's content. I recently started this one and it certainly takes some getting used to, but the amount I wish to share, what I choose to talk about, how and why allow ultimate control to fall within my hands. I like that. Exercise caution, of course. But, ultimately connect on a deeper level (which is definitely more me but it is your company?).
Social media has evolved into a necessity. Don't forget about it.
I think Brogan has it right when he says that it's about finding what works for you. Some may be fads, others lasting methods of communication. Either way, I think it's better to be involved then to be rendered socially inept by your lack of public presence.
Image Source: Simren Deogun