As more of the business world flattens with the expansion of online services, social networking is increasingly becoming a critical factor to success in many industries. Whether you're for a small businesses selling art at a craft fair or a Fortune 500 company trading on the stock exchange, social networking has the power to expand your brand among both your audience and fellow business owners. For the latter, entrepreneurs can take advantage of specialized social networks to meet, communicate share and partner with others.

Florida-based entrepreneur, business consultant and blogger Matthew Ringer recently posted an extensive list of the his top 40 Social Networking Sites Specifically for Small Business, Entrepreneurs, and Startups on his site Small Biz Bee. The list is an excellent resource for anyone looking to expand their professional network, but for those looking for a quick dose of business social networking, here are profiles of three great sites from Ringer's list for connecting with entrepreneurs.

LinkedIn

LinkedIn, an obvious choice, is the de facto business social network cementing its position as the top social network for entrepreneurs, startups and small businesses with over 50 million users as of October 2009. The widespread popularity of LinkedIn has turned the site into an excellent business directory and job board while making membership in the site as much of a professional necessity as a resume or portfolio. It wouldn't be surprising to see a site LinkedIn become a complete replacement for resumes in the near future.

PartnerUp

Ringer's number 3 spot goes to PartnerUp, which aims to do for small businesses and budding entrepreneurs what MeettheBoss does for executives by providing the opportunity for networking, collaboration and sharing. We recently told How to Avoid Mediocre Co-Founders and PartnerUp seems to be a excellent additional resource for finding your A team.

MeettheBoss

For the experienced entrepreneur, MeettheBoss narrows the business social network focus to the management level, providing a portal for executives and higher-ups to meet and communicate. With their unique tools for tracking your interests and activty and slick professional user interface, MeettheBoss is a great place for co-founders and CEOs to meet fellow senior managers to network and share information. The site also goes beyond social networking by providing an impressive set of features including exclusive articles and videos.

Some other great networks for connecting with entrepreneurs include StartupNation, BizNik and Entrepreneur Connect. Some interesting inclusions on Ringer's list included Qapacity, a network accompanying a website creating tool, and Ning, a site for creating and joining personalized social networks. Have some under-the-radar selections for great places for entrepreneurs to get together? Let us know in the comments.


Photo by Flickr user star5112.