Hey Mike -
Unfortunately, no. There is no way to "ask" a data source which workbooks are using it. Our public admin views don't support this, either.
Instead, you'll have to take the opposite approach - asking each workbook what data source it uses.
This tool might help you with that:
Thanks for that lead - that is exactly what I needed and more!
The TWB auditor does have a View called "What's connecting to which data" and that provides me with the insight I need to manage and clean up workbooks and data connections (including data sources).
What a great utility!