Social networking for readers of blogs
n/a
hosted
Popular open source web browser from Mozilla
Free/cheap Internet telephony and handy IM tool.
Web based social bookmarking lets you share online finds and discover new ones. Ground zero for tagging.
Powerful wiki software built to support the Wikipedia project
Hosted online surveys
Social networking for non-social purposes with a focus on professional development, networking for jobs and problem solving through the expertise of those in your extended network.
Web-based word processor and spreadsheet tool. Formerly Writely.
Social Bookmarking website
Change.org is a social network for hundreds of social causes and over 1 million nonprofit organizations.