Change format of Geolocation Balloons

I would like to change the format of the balloons that appear with item information when I click on an item's pin on the geolocation map. Specifically, I would the image that displays to be the thumbnail rather that fullsize version, and item's collection rather than title to display. Any hints on how to do so?

You will want to go into the plugin's views to get to the map's KML files: /plugins/Geolocation/views/shared/map/browse.kml.php

There you can change what is displayed at the title for the marker in the <Placemeark> section.
And currently a thumbnail is already called into the marker on the map.

You can edit the presentation of the display text by modifying the css file also found in the views:

Sorry for the long delay in response. We have been working on this on and off.

We are working in the file you mentioned. But are having a problem calling the collection name to display. We want to show the collection above the image in the balloon, and move the title below. We successfully moved the title, but cannot get the collection to display. We tried using the same code that calls the collection name to the item show page.