How best to display postal code data?

How have folks found the best way to visualize the Postal Code data within Tessitura? I'm trying to draw up some Analytics widgets/dashboards that will present things cleanly. I can draw up a scatter map, but that gets cluttered rather quickly.

Previously, we had mostly on-site sales, and our staff would ask the zip code survey question of each guest, and we could pull the results. Currently, our sales are online-only, so the survey question isn't possible.

How have you folks found it best to display the answer to the age-old question of 'Where are our guests coming from?'