FastAero adds Vista-like transparency to Windows XP
The utility is an executable file, which means you can unzip the program and run it without installing anything to your system. You can also decide whether to add a blur effect that partially obscures what's going on behind your window. If you disable this feature, you get a nice crisp clear, and somewhat blue look at what's behind window number 1.
The default language for FastAero is Polish, but you can change it to English by opening the config.ini file in a text editor and changing "polish" to "english."
I've never found these sorts of transparency effects to be particularly useful. There are other elements of Aero Glass that I'd much rather have on Windows XP, like the ability to see previews of running programs when you scroll your mouse over taskbar icons. For that, there's Visual ToolTip, which provides some, but not all of the functionality of that Aero Glass feature.