Erik Fantasia

With Map My Posts, you can easily create maps plotting the location of your posts, based upon your existing tags or categories.
<ul>
<li>3 map types available: Google Maps, Google Static Maps (PNG image), and Geochart Visualizations.</li>
<li>Embed maps on any page using the shortcodes [mmp-map], [mmp-staticmap], and [mmp-geochart]</li>
<li>Associate with a country or any specific map location.</li>
<li>Map My Posts uses existing category or tag names to help define country associations.</li>
<li>Widgets available to display maps in the sidebar.</li>
<li>Full control over size, colors, and click functions.</li>
<li>Perfect for travel bloggers, touring musicians, or anyone else that wants to Map My Posts!</li>
</ul>
Get Help
Please leave a message on <a href="https://wordpress.org/support/plugin/map-my-posts" rel="ugc">the wordpress.org support forum for Map My Posts</a>

Map My Posts

Less is more. Light is better. You original idea is awesome. Keep going ! These updates would be appreciate : 
- an update to use the new Google Map API,
- make it 100% WPML compatible (join translated locations using shortcode static map)
- be able to add our own custom taxonomy from the dashboard 

Your original idea is awesome

Map My Posts allows you to display a Google Map or Geochart visualization, associating map locations with your existing categories or tags.

LibraFire

LibraFire PinPoints plugin is a great tool for image mapping functionality with a really easy to use drag and drop ability.
1) You can set default settings for future plugin use. 
2) You can add unlimited number of markers on image per post. 
3) You can choose the size, color, background caption color, font size, opacity of the caption text (dot). 
4) You can choose on which post type the PinPoints control will show up.

LibraFire PinPoints

LF PinPoints is a simple drag and drop image mapping plugin with a caption functionality.

Map My Posts vs LibraFire PinPoints