As someone who actually has a pair (Gunnar Attache Phenoms,) and works a full time IT admin job, I believe I can answer the question for you. The answer is: They work for me, but YMMV.
My eyes would start aching after a few hours of looking at the LCD monitor I have at work. I tried all the recommended fixes: turning down the brightness, looking away for 15 seconds every 15 minutes (or whatever,) but my eyes still hurt, and would get really bloodshot. After I started using the Gunnars, my symptoms decreased by about 50-75%. In addition to using the glasses, getting a good night's sleep, and BLINKING (most important, my eye doctor tells me that the reason eyes get bloodshot is that our blinking reflex is retarded when we are looking at a screen.) keeps me from getting the eyestrain that I used to, even looking at a LCD screen for 10+ hours a day.
If this sounds like and advert for Gunnar, tough! I like mine and got a good deal at buy.com. The main downside is that they can make you look really, REALLY nerdy :P .
So be skeptical! I was, but I figured $50 was worth it if they worked.