Nice lists and links in this article from about controlling the facts about you, your company, and your product online.
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Managing Your Online Reputation

One of the easiest tools for tracking what Google knows about a topic is Google Alerts. Subscribe to a Google Alert and receive an email as soon as your search phrase (like your name or company) enters Google’s index.
You can subscribe to Technorati searches for your name or product in your feed reader. If you’re looking to monitor blog comments, check out previously mentioned co.mments which keeps you informed of the ongoing discussion.
MonitorThis aggregates data from 22 different sources
Your own blog is the most effective method for getting your message seen and heard.
Social media sites offer countless ways to participate in online community, and most of these profiles offer the added bonus of search engine visibility. Flickr, YouTube, Digg, Wikipedia, Facebook, and Twitter are six mainstream social media sites that feature results when you perform a web search.
One of the most important things you can do to control the message is to go to the source and communicate directly