Short answer:: Impracticale and usless for day to day use, but cool. If their cheap as heck ($20) why not...andy more and Id spend me money on something else.
Long explination::
They are 'neet/nifty' to play around with, but in practice its hard to use them long term. There are a few issues, the first is that using lcd shutter tech, means that you have to use a CRT....and a damn good one at that because your halving your refresh rate. You also will develop eyestrain/heaches whose onset timeframe depends on the person and the quality of their hardware. One of the bigest issues is that you will get a huge performance drop combined with a huge resolution drop (lets talk 50%). Even IF you can run at 1600x1200, you are now playing at 800x600.....and you had a nice framerate min of 40 fps before...now its in the 20's. So as you can see...its not a perfect solution.
It looks damn neat (Ive played AH with them and the depth is awsome) but its not not a practical day to day thing.
The only real way to go is 100% dedicated LCD micro display glasses, these avoid all the issues of 'flicker' and refresh rate, and somewhat lessen the strain on your hardware (your rendering 2 images at 1024x768 (1,572,864 pixels) instead of 1 image of 1600x1200 (1,920,000 pixels) with higher quality. Only issue now is last time I checked anything with 1024x768 resolution was into the kind of money I pay for a car
Hopefully these kind of specialy devices are being made obsolete with the new 3d LCD displays being produced now.