We would never cheat on the SAT or any other exam, of course, but if we were of that ilk we might consider taking along one these gadgets and claiming that it's just a standard calculator.
The "Pocket Prep" SAT and ACT tutors from the Princeton Review may not have all the answers one would need, but it should come close if it's doing its job right. The handheld device, which has a black and white LCD, includes drills "to maximize grammar and essay scores anywhere, anytime."
It does have a calculator, by the way. Granted, 5 by 4 inches might seem a tad large for one, but maybe it's just a really old model that we couldn't afford to replace. But to be doubly safe, perhaps there's a way to smuggle in a "StealthSwitch" for the benefit of those pesky test administrators walking by to snoop at the screen over our shoulders.