I've been playing in my sandbox with the Google API and have added a Google Map to my Property module.
It's all a bit clunky at the moment, but the principal's sound.

I've edited the view.item template to include the java for the google and create a DIV to hold the map.
At the moment the co-ordinates are just added to the property as a couple of custom fields and there is no validation (i.e. it will crash if no values are suppplied). 
I plan to retrieve the lat lon from the address using the geocode routines from Google - this would be best done in the add property form.

Any comments or suggestion gratefully received.

Most of the java is taken from an article written by Scott Jennings and published on the XMOD site the feedback form is also based on an idea of his - thanks Scott.   There's loads of info about the API on the Google Maps site and groups.

I've include the html for the view item below, the css just specifies the size of the DIV.  I've renamed the file with the extension jpg to add it as an attachment.

Has anyone add the geocode routines and the validation for Google Map.  I am trying to build a directory on our website.

Thanks for any help!

Tim Maler