http://www.linkedin.com is another business networking site you have to try if you have not seen it or heard about it before. LinkedIn is one of the world's biggest business networking sites that operates under the premises of you having to know or recommend your connections. You simply get invited by somebody you know to network with them and as a result you get access to that person's entire network. I have presently 3434 contacts or connections as LinkedIn prefers to call it and growing at a rate of 20 or more per week without any active participation from my side.
LinkedIn also provides premium pay services which will allow you to search for and directly address people you do not have in your network. Used wisely, LinkedIn can help you to drastically enhance your business reach within the world.
Please feel free to have a look at my public LinkedIn profile and send me an invitation if we are not connected directly to each other;