For Joomla 1.6 see below or here.
Requirements: Joomla Version: 1.5
JGMap displays a Google Map in any Joomla module position. The module parameters makes it easy to change width, height, position and zoom level of the map. Ability to optionally add default controls on the final map.
There is also a pro version with more features like custom marker, insert a article into the mark information window and much more