Multitasking is something akin to an urban legend.  Reality is all about serious, focused single-tasking, and you seem to be the man for that job already, so let me be brief (I'll really try this time; the first draft of this post had ballooned to nearly 800 words and I wasn't done yet, sorry ;-p ).

First off, you do need a list (though if you'd like, I could give you more tips on using 2 or, anecdotally, 3).  The list will physically or digitally maintain the things you need to do so your brain doesn't have to.  It's something like a safety net to your trapeze act of project juggling, so let it do its job while you do yours.

It can also be used as a picking tool.   Close your eyes and drop a fingertip/pen nib/stylus point onto the list and voila, choice made.   Alternatively, just take the next one down the list from the last one you worked on.

Its also a tool for excommunicating a task/project from your current sensoria.  If something sits on your list for awhile without you're touching it, you'll see what I mean.  You're not working on it because you're not interested and no one is calling for it.  Likely it doesn't need to be done, or at the very least, not any time in the next couple weeks, so take a moment to officially banish it from your list (this is were the 2nd/3rd lists come into play; ask, if you dare).

Second (and Last, scout's honor) off, you may want to look at "serial single-tasking".  You're excited to work on more than one project, or they have deadlines really close together, you could split your time up during a day in some fashion.  Figure out what works best for you so you can manage your personal resources for greatest productivity and least strain.

The simplest method, is to simply notice when your focus on your current task starts to fade.  Once you do, don't push.  Just wrap up what you're doing (if you feel the need) and then get up, literally.  Get your body out of chair shape, get your blood pumping a bit, pick your next task, take a moment get yourself set up to work on it, then go to town.  Lather, rinse, repeat until its time to call it a day.

Alot of folk lately have been talking using timers to signal work/break intervals. I haven't tried it myself (probably just because I don't have a good timer handy), but seems a likely alternative.  Mostly folk are just talking about keeping themselves sharp for putting in whole days' work in on the same project, but it should work just as well for signaling hops between projects.

Sorry for writing a blog post in response to yours, but at least I managed to cut this down (and trust me, the stuff I cut wasn't anywhere clever enough to be worth reading, so no worries).

Good luck,
Kensai
