You can definitely do it using the googlemap api and your own tileserver.

here is one little example:
http://econym.googlepages.com/example_custommap1.htm

and another one to display large images/photos using googlemaps:
http://www.casa.ucl.ac.uk/software/g...magecutter.asp

Since both of these use the googlemap api, you can use java to catch mouse click, add thumbtacks, etc.

-Rob A>