Leo Babauta has some nice tips for Zen-ifying your workspace.
On the subject of simplifying your computer: normally I run Linux, which tends to have a cleaner windowing environment. At work, though, I have to use Windows because it's what I need to support.
So I use BBLean on my computer instead of the normal Windows shell. It's a port of Fluxbox, and a lot more functional to me. BBLean has a simple plug-in infrastructure, skin support, multiple virtual desktops, and has much less visual clutter (no desktop icons). BB4Win has links to info, plugins, and variants.
It's nice to have the option of Explorer occasionally, even if I despise it, so I use Carapace to give me a shell menu at login. This is also a good way to have LiteStep or SharpE available too.
With no icons on the desktop, I need an alternative way to quickly run things. I use a combination of Launchy, StrokeIt, and RocketDock.
Launchy is a hotkey-activated launchbox with incremental search and plug-ins. It's also easily skinnable. It's great for finding something when your hands are already on the keyboard, so you don't have to reach over for the mouse and dig through a menu or find an icon. (Yes, this is a problem, especially on large screens - mine is 1600x1200 and set to small icons. Screen real-estate has a price...)
StrokeIt is a universal mouse gestures utility. It's something like a hotkey, but triggered by holding a mouse button and drawing a symbol. You can define custom symbols and custom triggers separately, and with varying contexts too. The program also learns how you draw the symbols over time. I really wish Linux had something like this...
RocketDock is essentially an ObjectDock clone, but freeware instead of shareware. It's compatible with Yz Dock and a couple of others, too. Eye-candy aside, I like having somewhere to put a few icons and have them both out of the way and easily accessible. The bubble-zoom effect alone makes it far superior to Windows Quicklaunch, because larger icons are easier to click quickly.
I've found that, with the exception of StrokeIt, any operating system has similar options available.