Mini-projector
Most of your presentations will be from your laptop, connected to projectors supplied by the school. But sometimes you just want to show a smaller group -- whether a seminar or a group of friends -- a slide show or a video without making them crowd around a computer.
For that, you can connect your digital video camera, iPod or iPhone to a personal portable projector like the Optoma PK100 Pico Pocket Projector (listed at $159.99, but often available for less). Measuring just 2 in. by 4 in. and weighing only 4 oz. (with battery), the DLP-based PK100 can project an image from 10 inches to 8.5 feet away at a size up to 59 inches.
The thing to know, though, is that it doesn't attach to your computer. It has a 2.5mm composite video/stereo jack and comes with a cable that connects to the standard yellow-red-white jacks from devices such as digital video cameras. An optional iPod connector kit ($39.99) lets you attach an iPod or iPhone via the dock and includes a spare battery.
Laptop cooler
Keeping your laptop from overheating is an important way to protect your most valuable (and expensive) academic tool, and that's where laptop coolers come in. We like the Targus Lap Chill Mat ($39.99), which is thoughtfully constructed of cushiony neoprene with built-in rubber stops to hold your laptop. The wedge design lets you orient your computer the way you like. (Targus' photos show the laptop angled toward the user, but ergonomics experts would probably recommend angling it away.)
The Lap Chill Mat's two fans blow your laptop's excess heat out the side; another advantage of the open wedge design is that it gives the hot air someplace to go. Just make sure you get the Lap Chill Mat and not the plain-old Chill Mat, which is not as cushy and won't feel as comfortable in your lap.
Next gadget: Seagate GoFlex TV HD media player