Of course, collaboration isn't limited to single documents. Most groups come together to work on one or more complex projects, and keeping everyone coordinated and on task can be a challenge.
Online workgroup and project management applications aim to simplify this process, allowing tasks to be assigned or claimed, work-in-progress to be shared, and progress toward milestones and ultimate goals to be tracked.
Many of these tools have whiteboards, conferencing and file storage built in to keep as much of the team's work in one place as possible. For quick-and-dirty collaboration, such as throwing together a presentation on the fly at a conference or for a sudden meeting, these added features can get in the way; you might be better off using a "mono-tasker" like the brainstorming or document-creation services above.
But for long-term team management, having everything in one interface can be worth the learning curve that comes with the more-complex tools below.
Wrike is a project management workspace that is distinguished by its e-mail-centric model -- projects and tasks can be added and shared by simply CC'ing e-mails with tasks to your Wrike account. Wrike uses folders to hierarchically arrange projects and subprojects, resources, reference materials or anything else you want to add.
Pricing is a little tricky; the rate depends on whether you want a user to be able to create, edit or assign tasks. For example, managers -- who can control task versions, create templates, build task dependencies and run reports -- cost $19.95 each per month; collaborators -- who can create and edit tasks, and view and update project plans -- cost $9.95 each per month. (This could get expensive for long projects with multiple team members, so in those situations you might want to consider one of the other project managers below.)
Somewhat more traditional than Wrike, WizeHive from PivotPoint Software allows you to sort projects and tasks into various workspaces, each with multiple pages, providing a great degree of granularity in how you view and act on tasks. Paid accounts start at $9 per month, though the free account offers plenty of space for small teams with only a few projects (1GB of storage for up to 15 pages or projects).
37signals' Basecamp has become something of a standard in project management apps, which among other things means it integrates with many other services and tools, including invoicing applications, time trackers, contact managers and reporting tools. For $24 a month, you can manage up to 15 projects and store up to 5GB of files -- plenty for most small teams.
The features are basic -- task lists, file sharing, and message boards -- but are incredibly easy to use, which makes Basecamp among the most intuitive project management apps out there.