Most people just work off the 'main window' in Logos (the one with all the icons). So this won't be helpful for them.
But if you work off multiple windows (I use 5), alt-tabbing (W7) to the front one is a pain just to find it. I found out by accident (which should have been obvious), that Logos will only open a single instance of the library. I keep an open library on the main window all the time. So a Control-L automatically switches me to the main window where I keep my lexicons, etc.
I assume the same principle will work for other tools that allow only a single instance. Windows itself has a numbered scheme but I always forget it between sessions.
