A portable printer, like one of those battery-operated bubble jet models that have received good reviews. Better solutions for batteries. I'm researching NiHM vs. NiCAD batteries for things like my QY70 and also for batteries for my laptop and my digital camera. Solutions to eliminate as many wires as possible, and simplify the wiring. One last hardware element that needs to be discussed is the video projection.
Ideal is XGA projection with the highest resolution.
LCD plate that sits on top of an overhead projector. Avoid this if at all possible. The latest Mac and PC laptops work great with SVGA quality video projection. Early Mac laptops require a special Mac cable to connect to the display projector. We covered projectors in more depth in one of our previous columns.