Not sure if it changes focus, but it does replace the mouse with an eye
As to multi-monitor setups, I'm now telecommuting most days. My new home
office desk has, from left to right, a 20" LCD on my PC, my work laptop
on a stand, and a 24" LCD. The LCDs are in portrait mode & the 24" is
switchable between my PC and the laptop using a KVM. That way my
primary display for both machines is always up and the secondary display
is switched to whichever machine I'm working on at the moment.