Does a multiple-monitor system increase productivity?

Multiple is more efficient, definitely. You can have double the amount of windows showing at once.
Plus even if it causes you to get distracted more easily, you eventually run out of distractions, if you’re seeing them two at once.

I have a dual monitor setup, and 2 laptops linked with a nifty app called synergy. I find that more productive, I can do completely independent tasks – and a whole bunch of more configurations.

Short answer is, yes. You can research, write papers, reference… a bunch of other tasks much faster. It’ll take some time to set up but once you’re going it’s great.

Distraction depends on what you put on said monitors :)

It depends. The last multi-monitor set up I dealt with on a regular basis was a 7-screen gaming cockpit with 10-speaker surround sound :P

Personally, I am so accustomed to multiple desktops only a key-press away on a single screen that I wouldn’t notice any real difference.

OMFG.. Buying a second was the best $200 I ever spent.

Left
Right

I can hack CSS in one screen and see a live preview in the other. All real-time. No need to save, switch windows, and refresh. This has saved me thousands of dollars.

It is definitely a good move. I run dual monitors, so I can keep an eye on things while I work on another program. At the moment I have Firefox on the left, and WMP, Google Desktop bar, and some file transferring on the right. It saves so much hassle switching windows and helps me keep the computer more organised.
The only problem is that the two screens are different from each other, so there are significant differences in colour quality which can look a little strange.

I run two and what it does? Saves time.

Maybe I just have too much screen to need more than one…

I run 4 2 24”’ and 2 22” I have found them to be very usefull but I usualy have a few remote desktop windows running all of the time.

I use two monitors at work and I have to say I feel constricted when at home.

Okay, thanks everybody.

I have dual monitors at work and it definitely makes me more productive. I can have two windows visible at once instead of having to mouse-click between them.

Helps tremendously. I have to develop documentation from many different sources, and it helps me to keep the main / new document on the big monitor right in front of me, and my various directories, source files and references in mini windows on the notebook screen.

It makes it so much easier to cut, paste, drag and view “what I want to get” in one screen, and “where it needs to go” in the other… and have them both visible at the same time.

Like some others said, it’s painful to work at home now with only the notebook screen open; like I’m working with 1980s technology. I can still do it, but it really sucks.