There are times when I would love to have a widget or two on my desktop, for those frequent activities. I'm always looking up words in the dictionary or just spell checking blog posts before submitting them, so having my dictionary widget on the desktop would save time. I am sure you have a widget you constantly use, so this will benefit you.
First you need to open up a terminal session via Applications > Utilities > Terminal and enter in the following line:
defaults write com.apple.dashboard devmode YES
Now we need to restart the dashboard which runs your widgets. The easiest way is to log out then in by clicking on the Apple in the upper right of the screen and selecting Log Out. After you have logged out, log back in. Press F12 to activate and load the dashboard. Once the dashboard has loaded, click and hold on the widget you wish to move to the desktop. While holding the mouse button down, move the widget around and then press F12 again. You should still be holding the mouse button down and now you can move the widget where you like on the desktop. The widget will always remain on top of other applications. To get that widget back on the dashboard, you can do this backwards. Click and hold the widget while dragging it around and then press F12.