Interesting question.
This section from the "Google Maps API Family" FAQ says:
Can I use Google Maps in my non-Web application?
Yes, the Google Maps APIs can now be used in Desktop applications, provided that they adhere to the other restrictions of the Terms of Service. Note that in order for a desktop application to be deemed "publicly accessible", there must be a publicly accessible webpage from which it can be downloaded. See Section 7.1c of the Terms of Service for more information.
The FAQ also explicitly includes the Static Maps API as part of the set of "Google Maps APIs" mentioned above:
What are the Google Maps APIs?
The Google Maps APIs give developers several ways of embedding Google Maps into web pages, and allows for either simple use or extensive customization. There are now several API offerings: Google Maps Javascript API, Google Maps API for Flash, Google Static Maps API. In addition, we also offer the Mapplets API to enable the creation of mini-applications that run inside Google Maps. Depending on your needs, you may find yourself using one or a combination of these APIs.
The problem is that Section 10.8 of the Terms of Use is still saying:
10 - Except as explicitly permitted in Section 7 or the Maps APIs Documentation, you must not (nor may you permit anyone else to):
...
10.8 - use the Static Maps API other than in an implementation in a web browser;
It seems that using the Static Maps in a non-Web application is explicitly permitted in the Maps APIs Documentation, but I wonder if Section 10.8 takes precedence.
I will try to seek further information about this issue, and will update this answer accordingly.
Related links: