[Toadling]

A few additions to abh19's excellent comments:

Originally Posted by abh19

No. A context is a location or environment which contains the tools you need to get an action done.

Contexts are perhaps a subset of the keywords one might use for tagging. As abh19 explained, a context is the required person, place, or thing to perform a task. How exactly you define your contexts depends a lot on how you work and how specific you want to be. You should certainly read David Allen's book to help get a better understanding of the concept. Browsing these forums will also provide some insight (there's a lot of variation in how people use contexts).

The Omni Group has mentioned before that they eventually intend to add support for custom metadata columns as well, which would presumably allow for free-format tagging, priorities, etc. in addition to existing metadata (contexts, durations, start and due dates, etc.).

Originally Posted by abh19

I believe that there is no integration with AddressBook, but you can assign an action to a person.

You can also drag vcards from Address Book and drop them into an action's note field to get a link to that person in Address Book.

Originally Posted by abh19

Not to individual actions, but an action group can have its own sequential or parallel attribute.

The sequential/parallel setting doesn't really apply on an individual action basis because it is an indication of how tasks are to be executed relative to other actions. So it only really makes sense to control that option on groups of actions.

As abh19 pointed out, you can set projects and arbitrary action groups to be sequential or parallel. But there is no such setting for individual actions.

-Dennis