During this recession it's more important than ever to get whatever you can for free.
Get Online Identities
This may sound obvious, but I'm constantly amazed at how many companies aren't yet embracing social media. Sign up for Twitter. Get a Facebook Group going. Create a company page on LinkedIn. Depending on your industry, get a MySpace page. There are also countless industry-specific online identities.
Create a Blog
Wordpress is quick, easy, and free. Publish content often (quality over quantity, however) to gain an audience.
Link the Identities Together
Install the Twitter App on Facebook so updating your Twitter status automatically updates your Facebook one. Encourage key employees to set up their own Twitter accounts and link them to their own Facebook statuses.
Sign up for Twitterfeed and link your blog(s) to it. Encourage key employees to do the same. Then, when anyone posts a new blog entry, this service automatically updates the associated Twitter accounts, and if the Twitter accounts are linked to Facebook, those Facebook statuses get updated automatically. Done right, your message gets blasted to thousands (or tens of thousands) instantly. You can also use Twitter's search to routinely monitor what people are saying about your company and your products and services.
If your customers take the time to write something about your brand, take the time to respond. The more responsive you are-even with negative issues-the higher your company's reputation will be. Studies show that when customers have a problem if they get a response from the company quickly they actually become more satisfied with the brand than if they had never had an issue to begin with.
The above tips represent a crash course in online reputation management and using social media to blast out blog posts, press releases, product announcements, and really anything your company has to say. Remember, in order to stay relevant, you need to push content out often, and respond quickly to what others are talking about. Do it right, and your social media presence will quickly become more relevant with a greater return on investment than anything offline.