For years, Kol’s Studio TwentyEight has put out outstanding visual applications, from themes to original art. HAL and other quality wallpapers can be found here. 

HAL9000 can be downloaded in many different resolutions.

Kol’s HAL9000 DeviantArt page

Kol’s DA gallery

Windows 7 includes a great desktop slideshow feature that rotates between several wallpaper images on a timed schedule. The problem is that the wallpaper dialog isn’t as easy to use as just, say, browsing through your files.

All you really have to do is select a bunch of them in Explorer, and then do "Set as desktop background" from the context menu. Yeah, it’s a Tiny Tip.

Tired of the default logon screen in Windows 7? You can easily swap it out with a new one with this tiny little utility. Just make sure to right-click and do Run as Administrator.

Windows 7 Logon screen editor

Jealous of the awesome Windows 7 wallpaper slideshow feature? You might not realize that Microsoft released a similar feature for XP years ago, and it also works on Vista. It’s hidden inside their "Winter Fun Pack", but the Tweaking with Vishal site has you covered with instructions on how to get to it.

Get Windows 7’s “Desktop Background SlideShow” Feature in XP and Vista Using Microsoft’s Official “Winter Fun Wallpaper Changer” Powertoy [Tweaking with Vishal]

If you ever wanted to be able to put a texture on your taskbar, you are in luck. This little utility loads a texture, or colorizes your taskbar. It’s simple, silly, and surprisingly works in Windows 7.

Texturized Taskbar

Want some unfreakingbelievable wallpaper images for your desktop? Head over to Desktopography and look through the amazing images, then download the version for your screen resolution. Awesome.

Desktopography

That’s right, you can actually get an application that gives you Aero Glass on your Windows XP machine. Basically, after installing it will modify your title bars to make them look like they are running Aero, complete with the transparent effects. Neat!

Border Skin