Just as I like to keep my home neat and organized, I like to keep my desktop pretty clean, too. Aside from hiding my dock that only has a few icons, and keeping my desktop free of files, I also like to have as little as possible on my menubar. By default, Apple doesn't make this too easy, especially with Mountain Lion's new notification center. Lately, I've been using an app called Bartender to clean things up.
Bartender allows you to hide menubar icons entirely, or move them to a separate "bartender" bar, which you can access from the menubar. It's especially handy to hide apps like Dropbox, which always appear in the menubar when active, or icons like the one for your wireless networks which you rarely need to access — but when you do need to, it's really nice to have up there. The default Bartender icons aren't the greatest (it comes with several), but it's easy to assign a custom one.
Currently Bartender is still in Beta, so there might still be a few kinks that need to be smoothed out. But I've been using it for the past month, and it's been working without issues. And, while in Beta, it's totally free.
So, if you're also on a never-ending quest to simplify your desktop, give Bartender a try — and let us know how it goes! It runs on Mac OS X 10.6+, and you can grab it here.