Since I use MacOS, I always find a way to make an application window to be always on top. I always use this feature in my Ubuntu box , using CompizFusion with emerald theme that has a button to make the window always in top in the title bar.
Finally I found a solution to make an application window to be always on top in Leopard using Afloat 2. Back then I was trying to use Afloat but it didn’t work. But the developer just made a new public beta release on 20 March 2008 that support Leopard.
Afloat can also make an application window to be transparent. But not all application can work with Afloat. Well at least it works on the built-in terminal