If you’re a GTD-disciple, you usually have a task description, project, due date and context. The first three are rather self-explanatory, but context deserves a little explanation. Context is the physical pre-conditions needed for you to complete a certain task. The original purpose for this was to enable to “put away” stuff you couldn’t complete right now (due to lack of contextual ability). The “putting away” is the fundamental principle of GTD, a context is it’s “big idea”.
Main problem with using context is that most people end up just a couple of contexts such as “computer”, “word”, “excel”, “email” and “phone”. Interesting thing about this is that all but the phone a “virtual contexts” (inside the computer)… and come to think of it, counting Skype or other VOIP-clients, so is the phone 
So many tasks have converged into being digital tasks, even shopping and going to the library have become redundant contexts in some cases. And with the laptop-computer you can really do all these things anywhere. When context was linked to physical spacetime, organizing by context made sense and was pretty easy… but with so many contexts converging digitally it’s not only affluent, it’s also confusing.
There is however, another benefit to using contexts (or tags in Things) in your support structure: it sharpens the focus of your “batches”. Batches are chunks of similar tasks which are done in sequence, based on the scientifically supported notion that executing many similar tasks at the same time is more efficient.
Working with batches allows you to stay focused. But you can do just fine without using context: “Project” and “Due date” is more than enough for creating batches.
For example: ideally, you have tasks broken down to fewer than twenty minutes. Filling 75 percent of you 8-day, that means you have about 20 tasks to complete in one day, plus another 5 for home. First of all, most people simply don’t have the discipline to actually break down their tasks to this level, which sort of leaves the whole context methodology a bit redundant. AND if you’re one of those able to break tasks down this good, you certainly have the mind to leave the batch adjustments to common sense. Also, creating focused batches assumes you won’t get disturbed when executing, which is a bit utopic in my view.
So here’s what you should do: start organizing by the “getting the right things done”. Start by making a list of stuff, project and when they should be done, “this week”, “next week” or “someday”. Right after dinner, make a list of the three things that your must get done tomorrow, adding their subtasks if necessary. Lable this list as “today”; no more than 10 tasks in total, preferably 5-6. The trick is to convert as many tasks as possible into actionable items, making you feel the “tick off” pleasure all the time. It’s addictive
First thing you wake up, start getting these things done, using projects as support structure and let context emerge naturally from a combination of device access, location and project. Focus on getting these things done, and fix emergency tasks if it’s really necessary. When you’re done, look at your watch. Can you go home? If yes, go home. If no, you move another task from the “this week” list to “today”. Look at your watch. Time to go home? Etc. Before leaving work, organize your tasks, shifting new things to be done to the “today” list.
Rinse, repeat.
But if you do have any suggestions, give it to me! And yeah, I’ll building it in Rails and (if I have time) a desktop-client in AIR. Always nice to have an excuse to polish up on those coding skills. 
