Phone Number Flash
From SykoSoft.Net iPhone Wiki
Phone#Flash example (fake number and names)
Using the application
The app presents a phone number and phone number type (mobile, home, etc.) and 4 names to select. Select the name. If you are correct a new number will appear, if you are incorrect the correct answer will be highlighted.
You can select just the groups of contacts to pick quiz numbers out of as well as saying to only select certain types of numbers (mobile, home, etc.)