[brianogilvie]

I find it helpful to think of contexts in terms of places, tools, peoples, and mindsets. Some of my contexts are places where I can choose to be (home, study, office, library, errands). Others are tools I might have (phone, computer--divided into Internet, offline, and email). Some are people I need to discuss things with. And then there are concepts or mindsets (reading, reflection, decision).

I find contexts useful not just for determining what I can do now where I am, but also where I should go--literally or figuratively. To take your errand example: I'll usually look over my errands context list before deciding to do errands; if the list is short I'll wait unless some errands are due soon or flagged as important. Similarly, I'll go to the library when my @library list gets long enough to merit an hour or two there. I'll meet with people on the subcontexts of my @agenda list when I can get several things done at once with them, or when something needs to be done with them soon.

In short, I find context lists useful for planning my day/week as well as for doing things. Those of us who have a lot of flexibility in where we can be at any given time can benefit from contexts not just as a way of getting things done where we happen to be but also, and perhaps even more so, as a way of planning where we have to be, physically or mentally.