Screen Sharing in Snow Leopard sends all keyboard shortcuts to the remote computer. As far as I know the only exceptions to this are the hard-coded "special features" of the F-keys on more recent keyboards (e.g. display brightness, Exposé, Dashboard, etc.) and the power button.
What they really need is a way to switch the focus of the keyboard & mouse between the local and remote machines without having to use the mouse to switch focus to a different window entirely.
If you do find a way to switch between remote displays with the keyboard, please let us know. That would be incredibly useful.
I'm glad you posted this thread. The first issue is that you're using the letter "x" instead of the Math multiplication symbol as shown in the menu. From the character viewer, I pasted in a multiplication symbol and the shortcuts appeared next to each display item. At the moment it still doesn't work because, like Seph explained, all the non-essential commands are sent to the remote desktop.
If you look in Screen Sharing preferences, there is a shortcut for toggling Control and Observe modes (Command + Alt + X). Switching to observer and then using the display shortcut will now switch displays (I used Command + Alt + 1 and 2).
Surprisingly the shortcuts still work even if you change the remote resolution (which changes the text in the menu item). Somebody who really knows about the operating system could maybe find a way to chain together multiple commands in a single glorious shortcut.
that sounds at least somewhat promising.
However I can't find
I'm looking at Screen Sharing --> Preferences and it only has one screen. using 10.6.8 as the screen sharing client and 10.5.X as the remote.
I too have been struggling with exactly the same issue. two monitors on host, one on client, no easy way to swtich back and forth without mousing up to the menu bar. i should mention that i'm using 10.8 but as i didn't find this thread in the 10.8 forum just thought i would chime in here.
i've come up with one workaround that is a slight improvement for me:
Option-Command-X (switch to observe mode) then immediately
Option-Command-1 (or 2, to switch to the other monitor) then
Option-Command-X again to switch back to observe mode
I know it seems a bit much, but it's actually pretty fast once you get used to it and since you're already holding down Option-Command it's really only three keystrokes. for me this is a bit faster than mousing up to the menubar. hope this helps someone.
On interesting thing (BUG?) i've found is that while in observe mode i am not able to quickly switch back and forth between monitors as expected using Option-Command-1 and Option-Command-2 in succession. For some reason I need to switch back to control mode and then back to observe mode before it will let me change monitors using key commands. another way it works is if i just click somewhere on the menu bar first which defeats the purpose of using key commands. pretty sure this is a bug.