I use a less time consuming way to "tag" tasks.
I have a list of standard words that I use when adding a task. For example: "buy", "call", "email", "follow up" etc
Furthermore, I have set up a series of "smart lists" that use matching words. For example I have a smart list that searches for the word "buy".
I freely add tasks knowing that when I use the "standard words" the tasks will find their way to the appropriate smart list. I find this method to be a real time saver.
Oh and this method works well with Siri!
Posted at 3:22am on November 10, 2012