I don't know about you, but flash cards played a big role in getting me through college unscathed. My short term memory has never been anything to write home about it, and we all know that memorizing some useless gunk is the key to testing stardom. So, I used flash cards to remember things like people (all 20 Greek philosophers whose names end in "cles"), rules and concepts (the difference between libel, slander, and murder), and key terms (economies of scale, supply and demand). All in all this served me pretty well.
Needless to say, my ears perked up when I heard about certification flash cards. Flash cards are a useful tool for mindless facts….but certification exams? Many certification exam questions are long answer and hands-on--not the sort of thing you'd use flash cards for.
So, I checked out www.certflashcardsonline.com (a redirect to a page on InformIT's website) to see for myself. And I have to say, the concept is fairly slick. Essentially, the "flash cards" are just online exams of a set amount of questions (usually a few hundred). You can sort them randomly (like flash cards) or only take questions based on your weak points (also like flash cards).
And for the not-so-concrete answers, the test gives you a text box to write in your answer, then spits out the blanket/recommended answer side-by-side with yours, so you can (honestly) rate whether it's correct or not. At the end of the test it gives you your score, and the implication is that if you pass these tests consistently then you'll pass the real test. Sort of like an SAT practice book.
There are some downsides, of course. One is the risk that you will simply learn all of the questions, rather than build a depth of understanding so that you're ready for anything come exam day. As far as how similar these flash cards are to the real exam, I don't really know. The vendor promises they're up to snuff, but I hear rumor that some companies exaggerate a tad to make a buck. Luckily, you can try them for yourself free and see if they're any good.
The price point is certainly appealing--each set of flash cards has about 300 cards (give or take 50), and costs about $20–$25. My recommendation would be that if you're going to go the self-study route, study first until you're pretty confident, and then go try these flash cards and see how you do. Better to blow $20 to find out you haven't mastered the subject material yet then leave the testing center empty-handed.
To learn more, check out the InformIT certification page.