There is a free update for existing users of WindowBlinds available. The most notable feature is the addition of the Explorer Background feature which allows you to apply a background, and adjust the opacity of the Explorer background. Other additions include various performance tweaks and enhancements.
The Explorer Background feature allows users to change the background of their explorer, along with the background color and opacity. There are 30 different background textures to choose from, including a “no texture” option that lets you set just the color and transparency of the Explorer background. WindowBlinds has a free download available for evaluation, and is $19.95 for the full enhanced version. WindowBlinds is also part of the Object Desktop suite of desktop enhancements.