My Maps @ Google Maps
Recently Google Maps finally released a new functionality called My Maps - it allows users to create their own maps in terms of putting own markers in locations they need, chose icons for them, add custom description and pictures for each marker bubble. There are also poligon and path tools available, so no you can draw any curve you like and outline a whole area and put your description for it. And finally, once saved, a link to this map can be sent to anybody or published as a regular URL link!
Just go to http://maps.google.com, click on My Maps and create an account for yourself. It requires to hava a Gmail account though. You can use any existing one or create an new one.
Here are some maps I was playing with: