So called Palmtop devices are rapidly becoming a must-have accessory among the tech types that are the target audience for study guide books. Now that 3Com is widely licensing the PalmOS, a number of vendors are making the devices and the prices are well under $200. Since you can pull out a Palm device and work with it in practically any environment, I feel that this is a perfect platform for a product that lets you practice for an exam whenever you have free time.
There is plenty of capacity in any PalmOS device for hundreds of questions, a glossary, and an adaptive scoring mechanism that could track a user's progress in various categories and use that information to optimize future testing and/or recommend study areas. Once a user has the application installed on a PalmOS device, it would be easy to delete old flashcard databases and install new ones as the user passes various exams.
I have created a prototype programmed in Java, using the preliminary KVM development kit. Question sets in our existing XML format are transformed into a compact form that is formatted to fit the Palm screen. The figure shows a question from the upcoming Linux Exam Prep book, with one option selected. This figure was captured from the Palm emulator software at double size.