With computer access so ubiquitous, an @computer context starts to feel like, oh, an
@Light context--I need light to do that task!
And if we were in an Elizabethan world, that context could totally make sense. Clear, bright, reliable light would be a thing only available in certain times and places, like the desk by the window in the daytime. Light would be the critical resource, in a sense sort of like "critical path"--it would be the resource most likely to be missing, and therefore the resource that should guide our choice to do those
@Light tasks when we get the chance.
In 2001, when a Google tells me the first GTD edition came out, we didn't all have a computer in our pocket. I suspect that far fewer of us had a laptop that we could carry wherever we were in the house, and that far fewer households had a computing device for every person. So the opportunity to sit down at the household's desktop computer in the den probably was the critical resource for a lot of tasks.
At work, more of us probably had an always-there computer; and for those of us who spent most of our work day at our desks, the computer might have already been sliding out of "critical resource" territory.
So what are the OTHER critical resources that might make more sense?
Possibilities:
@gotaseat: For a few years, one of our important software applications was desperately short of licenses--you would repeatedly try to log in, and it would tell you that all of the "seats" were filled. So if you got a seat, it would make sense to hang on to it until you finished all of the tasks that required that software.
@keyboard: Simply because we have computing devices in so many times and places, it my be relevant to track tasks that require an actual sit-down keyboard--especially at home, especially if you don't have a desk.
@fullsizebrowser: Similar. Several times, I've had tasks that I tried to do on my phone, realized that the needed mobile site is a nightmare, and resolved to do it when I get home. And then I forget, two or three times.
@switchavoidance: There are all those studies that say that task switching consumes a ton of time in settling back into the task. For that reason, it may make sense to group lots of your little "Oh, I have to..." tasks under one context to get them done and out of your mind at once.
You realized at lunch that Jane is the ideal person to assign that particular task to, you remember while on the train that you were supposed to tell Josh that the fix is ready for him to test, you run into Fred at the coffee machine and promise him you'll forward that mail that came from Jennifer, and so on. You entered those in your phone. When you get to your desk, you knock all those off, and thus increase your odds of being able to focus when you set everything to Do Not Disturb and sit down to write or code for two hours.
@desk: If you have a task or mode of work that requires your work computer AND that notebook full of hand-written notes AND that prospectus that came in the mail AND fast network access, the context should be one that encompasses the combination of all those resources.