I prepared exclusively using
- study material provided by ETS, i.e. practice books containing past exams (Ohio State University makes a total of 4 books available for download each containing 100 multiple choice questions and an answer sheet indicating the correct choice for each),
- online resources such as GREphysics.net and physgre for detailed answers, explanations, and helpful discussions.
While I wouldn't generally recommend this method as a great way for learning anything, least of all the often deep concepts encountered when tackling new physics, I believe it is likely the most effective way of preparing for the GREs.
However, and this leads to my question, the online resources I mentioned under 2 seem hopelessly antiquated. Just take a look at (and then flee again from) GREphysics.net to see what I mean.
There is no doubt that StackExchange could provide a vastly superior platform and forum for GRE preparation. Think about it: from MathJax support and commenting to the question-and-answer format and a large knowledgeable user base, it just seems like the perfect place for this.
Almost all of these test questions admit multiple ways to solve them. So whenever someone posts a GRE question he or she is struggling with (or one might one think about systematically adding all questions to this site), I would expect multiple answers in response. Popular vote can then identify the most concise/quick/accurate one. This rating of content, in my view, is one of the standout features of StackExchange and something none of the other GRE resources I encountered offered.
The only thing I'm unsure of is what the community thinks of this idea. Searching the site for posts mentioning GRE currently gives just 33 results and only a few of them contain actual exam questions. Is it just that there hasn't been a lot of interest from users or did the community decide for some reason to suppress any developments in this direction? In other words, what would happen if I went ahead and added a few GRE questions as a start?