Simon Wheatley

Allows authors to set their location, and then display it on a Google Map.
Adds a template tag: <code><?php al_list_authors(); ?></code> with the following available arguments:
<ul>
<li>include_protected_posts=1 : Include protected posts when calculating the latest post.</li>
<li>echo=1 : Whether to write the map and listing into the page, or return it (so you can assign the HTML to a variable).</li>
</ul>
The HTML output is fairly heavily classed, for ease of CSS styling, but if you need to adapt it you can. Create a directory in your theme called “view”, and a directory within that one called “author-listings”. Then copy the template files from <code>view/author-location/</code> in the plugin directory into your theme directory and amend as you need. If these files exist in these directories in your theme they will override the ones in the plugin directory. This is good because it means that when you update the plugin you can simply overwrite the old plugin directory as you haven’t changed any files in it. All hail <a href="http://urbangiraffe.com/" rel="nofollow ugc">John Godley</a> for the code which allows this magic to happen.
Plugin initially produced on behalf of <a href="http://www.puffbox.com" rel="nofollow ugc">Puffbox</a>.
Is this plugin lacking a feature you want? I’m happy to accept offers of feature sponsorship: <a href="http://www.simonwheatley.co.uk/contact-me/" rel="nofollow ugc">contact me</a> and we can discuss your ideas.
Any issues: <a href="http://www.simonwheatley.co.uk/contact-me/" rel="nofollow ugc">contact me</a>.

Author Location

Allows authors to set their location, and then display it on a Google Map.

Scott Cariss

This plugin is meant to be used by other developers and to be used together with themes and other plugins. Many themes and plugins use WordPress meta data table to store longitude and latitude co-ordinates for posts. While this works fine the meta data table cannot be indexed very well. Let’s take for example you have made a custom post type called ‘properties’. You create 100,000 posts all attached with latitude and longitude co-ordinates. You want your users to search for those properties in a 50 mile radius for example. Because of the method of which WordPress stores the meta data the query is slow especially when dealing with large amounts of data.
This plugin has been made to retro fit your current WordPress install. You as the developer select, using filters, what meta data you want to start capturing and this plugin will put the data in a table better optimized for storing latitude and longitude co-ordinates. Upon plugin activate existing data will be index and any data from then on.
Usage: 
Before activating set what meta keys you want this plugin to capture by using the filter ‘sc_geodatastore_meta_keys’. Your latitude and longitude values have to be stored in a single meta field like: <code>51.507334,-0.127682</code>
Example usage of the filter:
<pre><code>add_filter( 'sc_geodatastore_meta_keys', 'homes_for_sale_geodata' );
function homes_for_sale_geodata( $keys )
{
 $keys[] = "properties_address_coords";
 return $keys;
}
</code></pre>
Notice: 
This plugin is currently limited to only allowing one pair of co-ordinates per post. Maybe in a later version I will allow multiple pairs per post, but since this plugin was made to serve my purpose and it serves it well I see no reason to build upon it yet.

Geo Data Store

Stores lng/lat co-ordinates in a better optimized table. This plugin is meant for the use of other WordPress theme and plugin authors

Author Location vs Geo Data Store