Windows 7 keyboard shortcut to make current window transparent?

"#Space:: ;Show windows under pointed-at.
WinSet, Transparent, 25, A
return
#Space UP:: ;Restores window when you release the keys
WinSet, Transparent, OFF, A
return

AutoHotKey can do it! No fancy glass effects, but the window goes transparent. That's on Windows Key and Space."

"Similar to Phoshi, I use an AutoHotKey script that's a slightly modified version of this.

It uses Windows+Mouse Wheel Up/Down to adjust transparency, and Windows+Mouse Middle/Wheel Button to toggle off, or on to a preset. I find this control mechanism to be quite intuitive, allowing for rapid changes to window transparency as I work.

; Modified version of github.com/jvtrigueros/AutoHotkeyScripts/blob/master/Opacity/opacity.ahk

#WheelUp:: ; Increments transparency up by 3.375%
DetectHiddenWindows, on
WinGet, curtrans, Transparent, A
if ! curtrans
curtrans = 255
newtrans := curtrans + 8

WinSet, Transparent, %newtrans%, A
return

#WheelDown:: ; Increments transparency down by 3.375%
DetectHiddenWindows, on
WinGet, curtrans, Transparent, A
if ! curtrans
curtrans = 255
newtrans := curtrans - 8
if newtrans > 0
{
WinSet, Transparent, %newtrans%, A
}
return

#MButton:: ; Reset Transparency Settings
WinGet, curtrans, Transparent, A
if curtrans
{
WinSet, Transparent, 255, A
WinSet, Transparent, OFF, A
}
else
{
WinSet, Transparent, 200, A
}

return"