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.

freedimensional

Foursquare is rising in popularity, and will continue to grow. This plugin makes it easy to share your last check-in location without needing to worry about giving away personal info, and you don’t need to be an expert in mapping APIs!
The plugin places a Google map in a widget area and lets users enter their preferences over what they show, be it just the map, or the name of the place too, or the comment they left while there. Simple, effective, and sociable.
<h4>Features:</h4>
<ul>
<li>Offers an easy way to share your last check-in location with your blog’s readers.</li>
<li>Built on the Foursquare and Google Maps APIs, so expect blistering fast speeds.</li>
<li>Intuitive interface for editing options, with plenty more power under the hood.</li>
<li>Independent handling across multiple widget instances, using WordPress 2.8’s widget_class coolness.</li>
</ul>

Foursquare Map

Adds a map of your last Foursquare check-in location to a widget area, and makes it easy to share with your readers without giving away too much info.

Map My Posts vs Foursquare Map