I have my desktop wallpaper switching every minute. I think its cool, you may not, but this is how you can do it. Ubuntu repos have the wallpaper-tray app. Install with:
sudo apt-get install wallpaper-tray
Run on boot with a startup session. Viola.
Using gconf-editor navigate to applications - nautilus - desktop.
There are a couple of icons you can select to show on the desktop including “computer”, “home”, and “trash”.
VirtualBox seamless mode places the Windows taskbar above your Gnome or KDE taskbar. The Windows desktop is not displayed. When you open a Firefox or Internet Explorer web browser, from the Windows taskbar and save a file from a website, it will save to the Windows desktop. To compensate you can allow Windows to share the exact same desktop as your host Linux OS. You can save files from Windows web browsers directly to the shared Linux desktop.
Essential this is taking seamless a step further!!
First enable VirtualBox shared folder support for your desired guest OS. Make the shared folder either your Linux desktop directly, or simply your home directory. Then mount the shared folder in the guest OS:
net use x: \\vboxsvr\Desktop
Then open regedit. Locate the key:
[HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\User Shell Folders]
Change the desktop key to:
1) x: ; if you set the shared folder to be your Linux desktop folder
2) x:\Desktop ; if you set the shared folder to be your Linux home folder
Now just reboot your Windows guest OS and observe the seamless consolidation of your Windows and Linux desktops!!
This is one of my favorite Linux tweaks 
On my system notice that a virtual server environment is running in the top right window. That is the actual server environment that is hosting this website.
VirtualBox comes with the seamless mode option that can be enabled from the machine menu in a guest OS. If Microsoft Windows is the guest OS, and seamless mode is enabled, you will see the Windows taskbar above your Gnome or KDE task bar. You will not see the Windows desktop. Anything you run from the Windows taskbar will be in a window directly on your Linux desktop.
Seamless mode is for all practical purposes seamless. All your guest OS application are not run on a separate window, they are run in their own independent windows on the host OS desktop. It is truly a seamless blending of two operating system.
To enbale seamless mode with a hotkey, press your globally defined hotkey and “L”.
Take seamless mode to the next level (screenshot available)
A true Windows XP beginners introduction requires a step by step breakdown of deleting desktop icons, and emptying the trash. The first step is to boot your computer and have the desktop completely loaded as the following image shows (it happens to be in a VirtualBox guest OS, but none the less its the exact same procedure):
Notice the quantity of icons. They can be easily placed in folders with other similar content to reduce desktop clutter. Start by deleting icons that are completely unnecessary. You can right click on any icons, and select the delete option as show in the following picture:
After you click the delete option you will be prompted to verify your selection. Select yes as shown in the following screenshot:
Every time you repeat this process you will move icons to the trash folder which is also on your desktop. To delete the items in the trash right click the trash icon and select the “empty trash option”:
After you select the empty trash option you will be asked to verify your selection. Simply select yes to empty your trash:
If your desktop is 1024×768 or 1200×800 most likely you want a Virtual OS to be 800×600. Most Linux distributions will allow for resolution adjustment, but sometimes X gets in the way. X is designed to maximize the resolution based on settings in the xorg.conf file.
The simple solution to your desktop resolution problem is:
sudo nano /etc/X11/xorg.conf
Delete any reference to a resolution other than “800×600″. Now when X wants to maximize your resolution the 800×600 will be the maximum available.
RAM is the most crucial component necessary for graphical desktop and server function. On a desktop system that does not have enough RAM, you will not enjoy the system performance resulting from advanced graphical features such as Beryl or Compiz. The same holds true for a Windows XP system being upgraded to Vista; the advanced Windows graphical features really need a system with at least 1 Gigabyte of RAM. Just having enough RAM is not good, and in practice there should be at least 500 Megabytes of RAM left over after your computer has booted completely. This 500 Megabytes will be required for your web browsing, desktop folders, file copying, and all other internet based data transfers.
Internet based data transfers can consume a fair amount of RAM. As connections to the server increase, the load on the RAM will proportionally. I have recently upgraded my 1 Gigabyte system to 2 Gigabytes; before the system would operate at approximately 80% RAM capacity, and 20% page capacity. After the upgrade the system operates smoothly at 40%, and I have allocated 1 Gigabyte of RAM to my virtual server. Overall I recommend at minimum 2 Gigabytes of RAM for any web server that gets even a modicum of traffic; it is essential for stability, and uptime to minimize page file use.
