Looking for specific businesses or contacts within a company? Using tools like Manta.com or LinkedIn can help improve your chances of making a connection.
Like most tools, there is a learning curve. It is best to start off using these web service to listen and observe what people say and how they connect with others. Guy Kawasaki offers some tips on how to use LinkedIn. Though dated (the article is from January 2007) the information is still relevant and useful!