I'm using a multi-monitor setup and I often use the second screen as a display for a virtual machine. My problem is that I haven't found a good way to switch between the virtual machine and the host OS using only the keyboard. Naturally, when the VM is focused, it will intercept Alt+Tab to switch between its own apps. Same goes for other shortcuts like Win+1, etc.
Can you suggest a utility (or a built-in mechanism) that can provide such a "switch to the foreground application on the other display" shortcut?
The host OS can be either Windows or Mac OS X.