Backpack is a simple web-based service that allows you to make pages with to-do lists, notes, files, and images. Backpack also features a Calendar and Reminders that can be sent via email or to your cell phone at predefined times.  Tagging pages makes it easy to group related pages together.

Bubbl.us is a simple and free web application that lets you brainstorm online.

Ohloh is an open source network that connects people through the software they create and use

ReviewBasics is a powerful feedback gathering platform which allows professionals across many industries to exchange ideas, gather thoughts, and review various types
of creative, interactive, motion, and written content

Teamwork Project Manager is an easy-to-use online project management solution that helps managers, staff and clients work together more productively

The leading web based Project Management, Task and Time Tracking Solution, ProWorkflow is designed to increase business efficiency, and individual accountability. ProWorkflow allows you to manage projects, automate processes, and access your organization’s information online, anytime

Writeboards are shareable, web-based text documents that let you save every edit, roll back to any version, and easily compare changes.
User Writeboard to write solo or collaborate with others.