I'm experimenting with running two monitors this week. I'm curious to see if having more screen real estate will be of any benefit. I suspect that for transient activities, like e.mail, web apps, etc., it won't matter. For big writing projects, though, I find that I've got multiple windows that I flip back and forth among - previous documents, research materials, drafts, formatting instructions, etc. The limited side-by-side I've been able to do up until now has helped, so I'm looking forward to this test. I have a book chapter draft due next week, so this is a good time for this test.
I've been hesitant to do this for two reasons. Since the older spare monitor I'm using is running at a lower resolution than the primary, I'm a bit concerned that moving back and forth will exacerbate eye strain. I know you're supposed to do this with matching monitors, but this is a spare parts job, and beggars can't be choosers.
Also, I currently have LOOK AT ME, LOOK AT ME apps like e.mail, tweetdeck, etc. minimized. I'm leaving my Outlook window open in the secondary for today; if it gets to be too distracting, I could go back to a single for day-to-day, and only turn on the secondary when it's needed.
Not sure how that would work, but it's an experiment.