Maxivista is a cool utility that makes a notebook function as a second (or third, or fourth) monitor to a host PC.

I don’t have a second monitor, but can extend my desktop on main PC over to my notebook and drag Outlook over to that screen, or even split windows across the screens. The additional screen shows up in the control panel just if you’d added a real monitor.

It’s extremely easy to use and install. The protocol they are using works very well over LAN, and there are compressed versions that work well over wireless. The cost is right too, only $29.