A little while back the indiestore manager was updated so that you could enter Location (town/city) Post Code/Zip and Country information.

All these fields will be clickable and browsable via the indiestores at some point in the near future.
In fact you can browse indiestores via location now.
http://www.indiestore.com/locations/london

Update your artist details via the manager to make the most of these new feature and give your music more exposure.

Andrew.