Adding tags to tasks

Is there any plan to add tags to tasks?

I would find it very helpful to be able to add "at computer" or "phone" as a tag to a task, then to be able to search by these tags. This would allow me to only view the phone calls I needed to make when I'm in a good position to make a number of phone calls. This is one of the principles advocated by David Allen in his Getting Things Done system and I find it quite helpful.

In the meantime I've created a number of users for myself called phone, at computer, emails, etc. and I use these to split up my tasks. This works for now, but this is obviously not ideal.
john