Let me start by saying that I absolutely agree that there needs to be some sort of standardized measure of assessment within our applications and I understand the intentions of programs' use of the GRE. That said...
I had a horrific time with the GRE. My entire application (clinical PhD) was stellar, save for my very low, non-competitive GRE score. I was absolutely terrifed that this aspect of my application would single-handedly keep me out of graduate school and yes, I found that notion to be deeply, deeply unfair. I have tons of research experience, a very lengthy independent project, multiple poster presentations (including national conferences), a very high GPA, university and departmental honors.... and a lame test score. I applied to 11 schools and only received 3 interview invites (and I was honestly surprised to receive that many) despite some fantastically strong matches at several programs. I absolutely believe that my GRE score tanked my application at first glance at the majority of those programs and, had it been higher, I would have received significantly more interviews.
My story is a combination of what others above me have mentioned: I am a smart, determined individual who simply sucks at standardized tests. Between anxiety, issues with pacing, a poor educational background when it comes to even basic algebra (I have always struggled with it and wasn't taught it particularly well until I hit college, so while I get it now, it takes me longer to do computations that seem "logical" to other people), and so on. Those are not excuses, just explanations: it was just a huge, huge struggle for me. Suffice it to say, I worked my butt off for MONTHS... I ended up with what most individuals in clinical PhD world would consider a highly undesirable (and perhaps embarrassing) score, but I was content with it simply because I knew how hard I had worked for it.
Last week I received an offer at my top choice program (and, of course, accepted on the spot). I'm thrilled beyond explanation and incredibly proud that my determination and work ethic paid off and led me to a program that could not possibly be more perfect for me. That said, I take it very personally when people imply that the GRE accurately measures intelligence, accurately predicts graduate school success, or accurately indicates one's willingness to work hard (i.e., as one of the professors at my undergrad institution said, "if you score under a 1250, you didn't try. don't bother applying." ouch.). I am no less intelligent than those applicants who scored 1400+. Do they take the GRE better than I do? Yep. But that doesn't mean, in ANY way, that I won't excel in my graduate program or in my professional life or that I don't deserve a spot as much as they do. I truly cannot explain the visceral frustration of working so, so hard only to be bombarded with individuals stating that the GRE is easy, the concepts are simple, and a low score is predictive of grad school failure. It's simply NOT the case. (Note: this isn't directed at anyone in this thread... I'm solely referencing the distinctly discouraging words of several profs in my undergrad psych department.)
Take home message: the GRE is different for everybody and as such, I hate that it's weighed so heavily in the initial admissions stages (weeding out, etc.). Again, I certainly understand and agree with the need for some sort of standardized measure, but I also wholeheartedly believe that, particularly as current and to-be psychologists who understand the vast array of learning styles and intelligences, there HAS to be a more balanced method of comparing applicants (revamped standardized test or otherwise). I am indescribably grateful for my good fortune in this process, but I hate knowing that there are plenty of fantastic applicants out there who may never get a chance solely because of their GRE score. For some people, it's not a matter of "just sucking it up and making a 1250+ happen."
(heeyyy, I'm longwinded... thanks for humoring me!)