Google Product Manager Bret Taylor had this to say about the Google Maps Wallpaper generator. (It has been taken down as a result):
The Google Maps team recently noticed your Google Maps tile "stitcher" wallpaper maker at http://gmerge.2ni.net/. Google is always happy to see developers interested in our products and we commend you on the service. That said, we would appreciate it if you voluntarily remove your service and stop using Google Maps on your web site. The service violates the Maps Terms of Service available at http://www.google.com/help/terms_local.html, and jeopardizes our ability to make Google Maps available to the public because it encourages non-personal use of Google Maps.
If you have any questions or concerns, or if we have contacted the wrong people, please feel free to contact me directly. Otherwise, please let us know as soon as possible when the service has been removed.
Product Manager, Google Maps
I didn't get a chance to make the wallpapers I wanted to in time! :)