ETA: No need to update this anymore. See the Kiva list at Websites and Organizations. 
This is a list of microfinance web sites. I'll add to it as I learn more. If you have suggestions, I'll add them in.
Consultative Group to Assist the Poor: Nearly three billion poor people lack access to the basic financial services essential for them to manage their precarious lives. CGAP is a consortium of 33 public and private development agencies working together to expand access to financial services for the poor in developing countries. CGAP was created by these aid agencies and industry leaders to help create permanent financial services for the poor on a large scale (often referred to as "microfinance"). CGAP's unique membership structure and network of worldwide partners make it a potent convening platform to generate global consensus on standards and norms. As such, CGAP is a resource center for the entire microfinance industry, where it incubates and supports new ideas, innovative products, cutting-edge technology, novel mechanisms for delivering financial services, and concrete solutions to the challenges of expanding microfinance.
Grameen Bank: Grameen Bank Project was born in the village of Jobra, Bangladesh, in 1976. In 1983 it was transformed into a formal bank under a special law passed for its creation. It is owned by the poor borrowers of the bank who are mostly women. It works exclusively for them. Borrowers of Grameen Bank at present own 94 per cent of the total equity of the bank. Remaining 6 percent is owned by the government.
International Year of Microcredit 2005: Microcredit has been changing people's lives and revitalizing communities since the beginning of trade. Currently microentrepreneurs use loans as small as $100 to grow thriving businesses and, in turn, provide for their families, leading to strong and flourishing local economies. The Year of Microcredit 2005 calls for building inclusive financial sectors and strengthening the powerful, but untapped, entrepreneurial spirit existing in communities around the world to achieve the
Millennium Development Goals.
Microfinance Gateway: The Microfinance Gateway (the Gateway) is the most comprehensive source of information for and about the microfinance industry. It includes research and publications, discussion groups, specialized resource centers, organization and consultant profiles, and the latest news, events, and job opportunities in microfinance. Its guiding vision is to enable microfinance industry participants to generate value, innovate and engage in the free flow of ideas by effectively utilizing the Gateway's knowledge assets.
Microfinance Management Institute: The mission of the Microfinance Management Institute (MFMI) is to advance capacity in microfinance management worldwide. Leading experts in microfinance agree that insufficient management capacity and a relative dearth of technically skilled human resources are among the key constraints to the growth and outreach of the global microfinance sector.
MicroRate: MicroRate is the first rating agency specializing in the evaluation of microfinance institutions (MFIs). Its objective is to link MFIs with funding sources and in particular with international capital markets. MicroRate evaluations allow lenders and investors to measure risk and they thereby help to create the transparency without which financial markets cannot work.
MIX Market: The MIX MARKET ™ is a global, web-based, microfinance information platform. It provides information to sector actors and the public at large on microfinance institutions (MFIs) worldwide, public and private funds that invest in microfinance, MFI networks, raters/external evaluators, advisory firms, and governmental and regulatory agencies. The MIX Market seeks to develop a transparent information market to link MFIs worldwide with Investors and Donors and promote greater investment and information flows.
Kiva's profile 
United Nations Capital Development Fund: The UNCDF contributes to the achievement of the Millennium Development Goals in Least Developed Countries through a variety of innovative approaches in both local development and microfinance.
The World Wide Web Virtual Library on Microcredit and Microfinance: Microcredit and microfinance is not the answer to all the problems of poverty in developing countries, but it is indeed an 'inducer' to a great many actions that can lead to a better quality of life for the low-income groups. The Virtual Library on Microcredit is a repository of information on alternative, non-conventional financial systems and microfinance/microcredit issues.
