Although the example outlined above uses UK Postcode information, the same technique can be utilised if we had latitude/longitude information. The GeoDist functions work on a worldwide basis using latitude/longitude information to provide the same location-based functionality such as nearest location, minimum distances etc. These functions have also been extended to allow for the use of lists of locations from columns of files.
The UK Government publishes data on sold house prices in the UK (2). This data contains information on 26 million houses that have been sold between 1995 and the present day. The dataset is limited to location-based information (a number of different fields such as postcode, address, district, county etc), a little bit about it (type, freehold/leasehold, old/new) and sale information (date of sale, sale price).

This dataset is useful in this context to illustrate a nice use-case of using a file in an expression as we have such a large date range. An obvious starting point for analysis is to look at the change in house prices over time.