Windows in 3D switching Leopard

I randomly hit something or something strange happen in Leopard.

I toggled a screen where in MS Vista you can choose between opened windows in a 3D environment basically it stacks the windows so that you switch between them and see there contents.

Does anybody know how I did this? Is it just a fluke that it happened at all?


Also didn't know where to put this because I didn't see anything for Leopard only the newer ones. So if there is a place please move it to where it needs to go and sorry for posting in the wrong place.

 

I looked and i don't have spaces enabled and it didn't seem like it was expose.

the only way I can describe it is that its really close to Vista's except that the windows are in the middle and stacked not horizontal like Vista. If I can take a picture of my htpc I'll show you what I am taking about that I accidently hit or somehow got something like in Leopard.

EDIT: this is vista version's of what I got randomly in Leopard. its not quite the same but it closer to what happen than anything else.

 

I cannot take a picture of it because I don't know how I did it. I did not have time to take a picture when it first happened but I certainly know its not spaces since that seems to give a new desktop in which you can have many windows open. It was switching between windows like what I posted in vista but instead of horizontal like Vista it was vertical stacked.

 

I really do not know but it could be that. How does it open? Does it come from the top and down like lowering blinds on a real window?

 

thanks. I must have done that without realizing it then