v1.1 UPDATE: Okay, I lied about future development. Support has been added for any number of GPS links. Be aware, the plugin will simply try to convert any string with “::” in it to a GPS link, so if you’re in the habit of using that in your posts, I recommend finding the declaration for the $searchBit variable in the PHP, changing it to whatever delimiter you like, and adjusting your post syntax accordingly.
v1.0: 
This plugin will replace -one- properly formatted string in a post with a Google Maps link to the included GPS coordinates. The map will load in a new window/tab at zoom level=14, normal map view.
I wrote this to use when posting from my Nokia N810 handheld with WordPy, making it very easy to add a Google Maps link to my current location without using the wp-admin site, which is slow and clumsy on the handheld’s browser.
Features are minimal (only does the one thing, really), and usability could definitely use a bump. Even so, no additional development on this plugin is planned; I would suggest users looking for more comprehensive functionality take a look at WP Geo.
USAGE: 
You will need three bits of info: 
 A) GPS North-South coordinate 
 B) GPS East-West coordinate 
 C) Link text
Then, type that info using the following format into your post:
:gps:C::A::B:gps:
For example, if you wish to post a link to a map of GPS coordinates 32.970705,-116.955461 as reported by your GPS device/handheld/etc, simply type the following string into your post:
:gps:And this is an example link.::32.970705::-116.955461:gps:
And the plugin will convert that to the following markup when WordPress renders the post:
<a href='http://maps.google.com/maps?f=q&source=s_q&hl=en&z=14&geocode=&q=32.970705 ,+-116.955461' rel="nofollow ugc">And this is an example link.</a>

Google Maps GPS Link

Converts a properly formatted string with GPS coordinates in a post to a Google Maps link.

davidkeen

This plugin uses the Garmin Communicator Plugin to allow downloading of GPX data to connected Garmin GPS devices.

Google Maps GPS Link vs GPXconnect