[composed before the question got moved to the old thread - just a comment, not a complaint]
I think you are asking for context tagging. It is a request that many have asked for, but one that may or may not be addressed in a future OF release.
If you must have this capability now, then you may want to look at
Things. Someone posted a link in another thread, but the review can be found in this
blog post.
What OF does support is hierarchical contexts. Which sort of accomplishes what you want:
Phone
Phone:John
Phone:Mary
Email
Email:John
Email:Mary
OR
John
John:Phone
John:Email
John:Meeting
Mary
Mary:Phone
Mary:Email
Mary:Meeting
You get the idea. This approach may work better for you with a hierarchy that is location based, and then activity based. Then create a context group for each person with whom you regularly need to utilize to complete a task. This might look something like:
Office
Office:Phone
Office:Email
Office:Meeting
Office:Mac
People
People:John
People:Mary
If you only need a few "People" contexts, you could just as easily dispense with the People group, and just have a context for each person.