I wouldn't be so sure. I know that certain professional 3D rendering and CAD video cards support two outputs from a single port using certain types of splitters, but I'm not sure if those would work with the PowerBook. I also don't think a dual-link DVI port can be split into two standard DVI ports. If you have a 15" or 17" PowerBook and need triple monitors, I think the only solution would be the VTBook
cardbus video card.