CrystalXP.net

Here two free portable applications made by Solo-Dev : TransTaskbar and Transparent Context Menu.

Discovered through the web site of Vishal-Gupta, these two applications will allow you to give transparency to :

your Start Menu and your Taskbar with TransTaskbar



your context menus (desktop, files... menu which is shown when you right-click on something) with Transparent Context Menu



Available for Windows XP, Vista and Windows 7, you can download TransTaskbar here and if you want to try Transparent Context Menu, you can click there.