No because there is no video input at all on a powerbook , and definitely no way of making it share it's CPU loads, unless you want to set up a network between them and use a program to make them render collectively for that one program.
You can't do it directly, you need to have both computers on the same LAN and use specific software. Assuming you're using MAC, you should look for "ScreenRecycler"
Another solution would be "Synergy".
Both computers should be connected to the same network,then download the program called screen recycler to both computers and follow the instructions on the screen recycler website.
In order to use power book as a second display you will first need to have one of the other Microsoft problems running. Once one of these is running everything should be fine.