Sprint’s business site now has amazingly-detailed coverage maps that provide street-by-street coverage information and even shows upcoming towers in the detailed maps.
The system appears to use Java 2, so if you use Windows you will probably have to switch to the Sun Java VM (even Microsoft recommends this, they have discontinued development and will stop patching it at the end of the year). Mac OS X users already have Java 2, and OS 9 users need to buy a new Mac 🙂
Of course, most affiliate areas are not shown. They are asking for feedback, so tell them that you want affiliate towers listed!