The quick tip in the new Sitepoint tech times I received yesterday suggested to Put my CSS at work this Christmas. It's fairly simple actually, pick an area with a flat coloured background, create a seasonal variation in your image editor and ad a background propertie to your CSS. The background I am using is a preped one by Kevin Yank, the editor of the tech times. I simply added the following to my CSS:
body {
background: #708DAB
url(/blog/2003/12/images/flakes.gif)
repeat-y left;
}