Following suggestions here, I've been playing with Dexpot for a few weeks now. At first it was just a toy that I wanted to play with and try out, but it's become pretty useful to me, and I thought others might me interested in how I've been using it.
For me, I've found two key advantages: protection from
distractions, and protection from mangling due to
resolution changes. To take advantage of this, I've set up four virtual desktops:
General,
Games, and
Development. General holds my email, web browser, etc.; Development holds Visual Studio, MSDN docs, and related tools; games should be obvious.
Distractions - When I'm doing development I don't want to be distracted (which is, unfortunately, all too easy (
ooh, look, there goes a bunny 
). The things that can distracty me, like Outlook or Firefox, are kept away from my development desktop, so when I'm trying to concentrate, I
can't notice that an email has just arrived.
Layout mangling - All work and no play makes Chris a dull boy; he needs a game once in a while. Games love to suck the display into all kinds of goofy resolutions, and when they do this, other windows get resized and shuffled around. I'm very anal about my desktop, and this drives my up the wall. By keeping games in a single desktop, and only ever starting them there, I ensure that the serious stuff in the other desktops aren't affected by resolution changes.
So this has been a pretty successful experiment and I plan to stay with it.
