Remember, there is no such thing as true multitasking. Well, anyway, personally, I haven't been very good at that. Conversely, my single-track tasking is pretty good. I can maintain high CPU processing around 6 hours straight (not sure about now, but I remember I could just a year or so ago). (high CPU processing = solving science olympiad questions)
The main problem is, even if the various tasks are all closer related (i.e. all the things on the computer), e.g. while waiting for my program to install, I surf the web and monitor and optimise my torrents, I tend to follow one path and go straight down to the end (which tends to find no end) and thus neglect the other tasks. Worse still, when I do find a chance to interrupt, i.e. a pause while waiting for someone to return a comment on facebook, or to see the effect of the settings in my torrent client, I tend to have already forgotten about other tasks waiting in line. My default response to an interruption opportunity is thus, to go back to a task which is the most highly probable of generating new info for me to take care of, which usually is facebook.
While this may sound dry and all, I think it's worth considering this default response, what's yours? By having my default response as such, I have been kinda wasting time, because I tend to forget to go back to a previous task which I was waiting for to complete. If this default response is changed to something else, my efficiency will probably increase.
Now the question is, what's the right default response to an interruption opportunity? This response has to be habitual, which is easy to form by neuro-linguistic programming, but the main concern is that the response must not take too long. Considering "What was I waiting for?" is probably too long, since it requires a memory search of current running tasks. And "cycle through all possible tasks" might be faster, but it can't always be done since some tasks like "google this" will not have a window or tab to function as a reminder. There's no point writing down or keying in the list of tasks opened since that in itself wastes a hell lot of time... wow this is kinda difficult.
Ok, I think, I'm gonna try to place reminder tokens of tasks to be followed up upon, somewhere around, and together with the default response "look for: reminder_token, if reminder_token=null, proceed to most probable task", it should help I hope...