I can't imagine how a second monitor could improve productivity for anyone. What would you display on it other than a distracting irc room or twitter feed? Technological hubris at it's most despicable I say :)
I have three monitors and it saves me a tonne of headache. Left to right:
1. (Ubuntu) Project Firebug Browser, Reference Browser, FTP
2. (Ubuntu) Source Editor, Email, Console
3. (Win 7) Photoshop, IE Tester, MS Office junk
I can easily live with two, but there was a spare old monitor kicking about, so I absconded with it. With only one monitor, I spend a lot of clicking through the task bar trying to figure out what window I need next. With lots of monitors, I'm able to remain focused by just glancing back and forth between monitors.
• Editor on one monitor, running application on the other.
• Editor on one monitor, documentation on the other.
• More source code at once.
I mean, seriously, have you never run out of screen real estate when you have five source code files, a web inspector window, and a browser window open?
