LinkedIn is an international community for businesses and professionals with features fine-tuned to help you use resources and share ideas with other professionals world-wide.
An online real estate marketplace and social network for home buyers, home sellers, and real estate agents.
A social network where users propose and fund projects.
Jigsaw is a wikipedia-like database of business contacts where your access to records depends on your contributions to the community.
XING is a network of professional contacts to search for jobs and companies, share ideas, and find professionals in any area of expertise.
Spoke provides tools and information to help you organize and connect with business people worldwide.
A social network that connects bloggers with advertisers.
A network where business owners are paid to share, discuss and collaborate.
A microfinancing community connecting lenders and entrepreneurs with the goal of alleviating poverty.
Professional world-wide social network dedicated to networking, business, and careers.