If you're using Java, TestNG will help you solve this problem more effectively than junit; see http://www.testng.org for details. Dan Fabulich has written a simple example of a test driven by a data provider; I've attached that code as DataProviderExample.java. (Don't bother him for support with this. But feel free to submit fixes.)
I've also attached an example of how to read from an Excel spreadsheet from Java.