The two notebooks reviewed here use a technology called frame sequential stereoscopic 3D that mimics the way we see 3D by sending individual images to each eye. Their Nvidia graphics systems create and display a stream of images that alternate between right and left frames that are intended for viewing by the right and left eyes.
This is where the funky black plastic glasses come in. Frame sequential 3D uses what are called active shutter glasses, which have a pair of lenses made out of small LCD panels. As the images switch from one meant for the right eye to one meant for the left eye, the lenses alternate between being opaque and transparent so that only one eye sees the scene -- 120 times a second. An infrared emitter on the system sends out a synchronization signal to the glasses to make sure it all works properly.
(Incidentally, these are not the same as the glasses you're given in movie theaters, which use lenses that work with images that are polarized by 90 degrees; each eye only gets the image that is correctly polarized for that eye.)
The result is that the brain is tricked into constructing a 3D world around this two-fold visual input. How well it works depends on the 3D movie or game as much as on the system it is played on. Without the glasses to get the correct frames to the correct eyes frame sequential 3D images onscreen look like a confusing double image.
If the glasses are a deal-breaker for you, by the end of the year, there may be a new generation of 3D systems that don't require the glasses. Some initial tries can be found in HTC's EVO 3D smartphone and Nintendo's 3DS game machine. Toshiba is also working on a glasses-free 3D laptop.