Can I use my powerbook as a monitor for my mac pro?

Near as I can figure, there's no easy way to get there; doesn't appear to be a software/settings option to configure the notebook's display as an auxilliary monitor - other way around, yeah, display the notebook's output on an outboard monitor, but that's not what you're after.

Note - that's just as near as I can figure - the only Mac I've got right now is an older G4 PowerBook. Might be something different about yours, but I doubt it.