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Depends on your skills with other software. If you know SQL, it's relatively easy. You could also do it via the SDK but that's a long learning curve. I'm also quite close to releasing an XML output plugin, which you could then use to create lists of unique locations.
I don't think so. It does export a text file listing all the visible / selected images, but not a list of unique values in a specific field. You could use it to get there by exporting a complete text file, and taking the text file into Excel - use a pivot table or the data filter commands to extract the unique location values.