Is there a sample database available with GridMonger?
Yes. More than one, actually. The GridMonger release itself contains a small sample database which contains 1,000 ZIP codes entries. These entries also include additional information that, basically, is worthless filler meant to demonstrate the application.
GridMonger is also presently incorporated into the free FedexMonger, AccessMonger Lite, SitePeeker and UPSRateMonger tools. You can download one or all of those in addition to GridMonger, use the included configuration file and instantly have another running sample database application.