I have grid display #1(the "tic tac toe") enabled, and enabled under Menu Functions. However, I can not get this display (grid#1) to turn on in the viewfinder, only on the lcd in Live View. I can only see grid #2 even when grid #1 is selected. What am I missing? Thanks.

Unless this is a feature of the 7D which is not available on the 5D mk II, you won't see the grid patterns in the viewfinder, as the viewfinder is showing you what the lens is seeing (via a mirror and a prism). The LCD is a digital representation of what is coming through the lens, with other information (shutter, aperture, ISO, etc, etc) added. If you select the grid display, that's just another overlay that will be shown on the LCD. It can't be displayed on the viewfinder since there's no mechanism to project the grid onto the viewfinder. You can, of course, replace the ground glass screen in the viewfinder, with a different one, which may have a grid physically ground into it, but there's no way to "turn it off", without removing it again.

In the menu the second yellow section (with the spanner icon) at the bottom is VF grid display, this enables/disables the grid in the viewfinder on a 7D

Interesting!! I didn't know the 7D had that feature. The 5D mk II does not. I feel cheated! :-)

I have enabled it, but Grid #1 will not display in the viewfinder, only on the lcd in Live View. What am I missing? Thanks.

Ah, I think I see what your saying now, grid #1 and grid #2 only apply to the LCD, there is only 1 grid type in the veiwfinder which I guess looks a bit like grid #2.

Julian, don't feel too cheated, the 7D has a fixed screen so no ability to interchange to more specialized screens!

Thanks...too bad...I am not too fond of using the lcd when using the camera, prefer the viewfinder.