Apple's "iPhone Development Guide" suggests on page 62 that "Because application tests run only on a device, you can also use these tests to perform hardware testing...".
I'd like to run my OCUnit test cases in the simulator as well -- but haven't figured out how to do that. Is it possible? Or do I have to use Google's toolkit instead? http://code.google.com/p/google-toolbox-for-mac/
Took a day of digging around, but it appears that OCUnit does not allow tests on the simulator but on device only. Google Toolkit for Mac is better suited for testing on the simulator: http://code.google.com/p/google-toolbox-for-mac/wiki/iPhoneUnitTesting