Multiple Monitor Madness
If you think 3 monitors is madness, check out this system for sale on eBay:

Here's the text of the auction which is currently up to $7,199 as of this wriitng:
The item you are bidding on is a Dell Super Computer with Eight 20 inch Flat Screen Ultra Sharp Monitors with 1600 x 1200 Resolution and 5.1 Cambridge SoundWorks Speakers with Bass Cube. Windows XP Pro Operating System. The Computer items were purchased new from Dell in 03/2004. The Computer is a Precision Workstation 450 with Two 3.20 GHz Xeon Processors with 2MB L3 Cache 533FSB, 4GB 266 MHz Double Data Rate SDram , Two 146GB SCSI U320 10K RPM Hard Drives, 8X DVD+RW/+R and 16X DVD, Two Colorgraphic Xentera GT 4 Video Cards to run the 8 Screens, Cordless Mouse, Cordless Keypad, Dell 3 in 1 Printer/Fax/Scanner, 3 Ergotron Adjustable Monitor Stands, Surge Protectors, 3 Sets of Smaller Speakers for watching TV or Security System on Individual Monitors. The Monitors can be arranged in any configuration. Over $20,000 Invested. Works Perfect. Great for Photos, Charts, Graphs, Trading Stocks, Security System. I should have all the original boxes for shipping.
Interestingly, Google's Larry Page was a very early three monitor enthusiast

that picture is from this San Francisco Chronicle interview circa Late 2000:
Chronicle: What technology do you use at work?
Page: I have a weird setup in my office. I have one computer with three monitors: one flat-screen monitor and two regular ones. I have my browser on one screen, my schedule on another and my e-mail on another. I can drag things to different screens. I also have a projector. So if I'm talking with everyone in my office, I can move stuff onto a big screen.
Three to four monitors is fairly easy to achieve today, mostly because hardware has improved; today you can easily buy motherboards with two video card slots. And video cards commonly come with dual display outputs standard. This was definitely not the case back in 2000!
Believe it or not, the OS was actually ahead of the hardware: Windows 98 supported up to 10 monitors right out of the box.