Add "study guide" to the long list of tricks you can do with your iPhone. Cram ($9.99) is a solid application that lets you create and import tests on any topic. You'll be able to take scored multiple choice quizzes or go into study mode, in which Cram provides you with a series of digital flash cards. Cram will flash the question and you decide with a click when the answer appears.
Cram is fairly simple to use, but there is a correct order for getting started. For instance, you had best register for Cram online before you attempt to use it; you can't currently register from the iPhone.
If you're planning to create your own test material in preparation of an exam, you should consider crafting that online as well. While you can technically--and fairly easily--compose questions and answers within Cram, typing a series of multiple choice entries is faster work with a standard keyboard. If you intend to reuse multiple choice answers to trip up yourself or others, your computer's magical cutting and pasting abilities are indispensable.
When it's time to import a test, you log into Cram from the iPhone and select the test you'd like. They transfer in seconds. You'll also be able to import public tests that others have created. What Cram's application doesn't tell you is that your personal log-in is useless for getting these. Instead, enter 'cram' as the log-in and the password to access shared files. At the time of writing, 116 tests were public, and some are quite useful.
The principle problem with relying on others' tests is that they're often under 20 questions in length. The shorter they are, the faster you'll ace them and move on.
There are also a few more features the Cram team should think about bestowing. The first is a search bar within the public test gallery to help you identify them by topic or name. The second is a button that lets you learn more about the public test--for example, what differentiates African Capitals numbered 1 through 5?
Even without these additions, Cram makes a good quizzing tool for students who respond well to flash cards, as well as teachers and study groups. You'll also get ecological bonus points for ditching your paper flash cards and going digital. The very recent price reduction from about $16 to $10 makes Cram that much more attractive.
Related download: Cram for BlackBerry