Cable Management:
http://lifehacker.com/search/cable%20management/
Clutter:
http://lifehacker.com/tag/cluttercleanout/
EDIT:
Now what used to be a huge rats nest of cables has been pared down to the MagSafe, the speaker power unit, and a single power strip, which is much tidier. My personal setup is very similar to his, except that I use an external screen with my MacBook instead of the laptop screen, and I connect it all together with the new Henge Dock that just came out.
keyboard (could be replaced with wireless) external hard drive - time machine. i prefer it this way than over wireless iphone dock (hidden underneath macbook) speakers - they are usb based
the second power board is simply there because i may need it in the future.
Cable management is essential for a data center where multiple sets of maintenance hands, multiple owners, SLAs, fire codes, and cooling/venting needs demand organized layouts.
Cable management is also important for tight spaces (inside walls) and extremely low-duty-cycle, but mission-critical wiring such as a home's breaker-box.
Is it necessary for the typical modern desktop with a few AC Power, networking, and USB cords?
Um, NO.
And on the desk I use some plastic tubes that hold several cables together, also from Ikea.