Recs.
Updated
Asana is a web and mobile application designed to enable teamwork without email. Asana puts conversations and tasks together, with the hope that teams can get more done with less effort.
Specs
Pros
Pro Simple workflow
The Asana task workflow within a project is broken down into "Today", "Upcoming" and "Later".
The tasks themselves have the status of either done or not done. There is also a sub-task feature to group tasks together.
Tasks can be assigned to each other and are stored in the "Inbox" view for processing. This replaces email for some team communication.
Pro Very polished interface
Teams can have private (only visible to project members) and public (visible to anyone in the team) projects. Each member can also have their own personal projects.
Tasks can be viewed in list and calendar views. It's possible to display only the tasks assigned to the user or tasks organized by project or team.
Lists of tasks can be divided into sections and organized in many different ways - tasks that still have to be done, tasks that have been completed, by due date, by assignee, by popularity.
Single tasks can exist in multiple projects.
Expanding a task will allow adding things like subtasks, tags, attachments as well as leaving comments and subscribing to a task via RSS.
There's a separate view for attachments.
Search for finding stuff quickly.
Cons
Con UX Design is overly opinionated
Asana forces a user to conform to their worldview of what the optimal workflow is. Workflow's are constantly changing. As such, an opinionated design is not always ideal for project management depending on how you like to organise your projects.