[floatinglist]

A lot has been written, so this post is more of a vote for multiple contexts.

Speed
It takes time to decide if its better to place something in a specific context. It is faster to skip this decision and simply assign multiple contexts. Sometimes a task really can be done in more than one place.

Ease of Implementation
Why have a workaround when the database backend easily allows for this tagging-like feature?

UI Problem?
In the lists, separate different contexts using commas (canonical grammar) or the @ symbol (canonical GTD). Show the same task multiple times when viewing all contexts. Checking the task off will check it off in all contexts. The power of the context view is that you can focus on one context while working, so the awkwardness of seeing the same task listed multiple times should come up only when you're reviewing things, and when you're reviewing things, this will help make it easier to see what tasks have multiple contexts (to allow you to review your decision to place those tasks into multiple contexts).

Like Paper
This is easy to do on paper, and it is what I did on paper. If you don't want to use the feature, it remains optional and out of the way.

Optionally Out of Sight
Allowing this gets rid of a nuisance for those who wish to use it, and allows a better way to work out of context mode. If you don't use this, it stays out of the way.