Semi-Transparent Windows

Sometimes I work on the command line, or am editing some file in a text editor. But I want to look at one window while I type in another. Even with my two screens, windows must sometimes overlap, but when this is necessary a semi-transparent foreground window can be handy, so the window behind can still be read.

Yes, Aero in windows lets your windows' border be semi-transparent. But it's only a thin border, and you still cant read what's behind as the background is blurred. I really dont understand the usability advantage of this feature. Seems a bit useless to me.

There's also the 'Glasser' extension for Firefox that makes Firefox's toolbars transparent in a similar way. But that only adds a bit of consistency, without much of a benefit.

Slightly more useful, is 'Glass CMD for Vista' that makes cmd.exe semi-transparent, but again, the background is blurred so you cant read what is behind. There is also 'Glass Notepad'.

What about disabling blur? It is possible with a registry hack, or by replacing DLLs on Windows 7. Neither of theas seem like a very clean solution.

Then I found Glass2k. And it even works on Windows 7 x64! I just press Ctrl-Shift-[1 to 9] to vary the transparency. And there is no blur. Perfect.