Geocoding

"Maximize the editor" and set your browser for "full screen" and Mediawiki+FCKeditor starts to look just like another word procesor. And that's really excellent. For awhile, having to learn a new markup language served as a sort of IQ test for web site visitors. But, spammers soon figured it out. So, now there's really no good reason to not use a common visual editor, like FCKeditor.
Of course, Mediawiki+FCKeditor isn't complete.
But, it's not horribly broken, either.
It worked after a handful of tries.
FCKeditor doesn't know how to handle some extensions.
FCKeditor doesn't know ANYTHING about slmap tags!
Adding more "Special Tags" to FCKeditor is a kludge.

Proposed Solution

Add "Insert/Edit Location" Button
It should work just like "Insert/Edit Link" Button, attaching the tag to the highlighted text or at the current cursor position if no text is highlighted.
Asking the user to enter Lat/Long is the wrong solution!
So, we start with a "Course Acquifoesition" in which we search for the highlight name (or the user's current IP address if nothing is highlighted) in a database of common names.
There are many common name databases.
There is one cheap (free), easy and ~90% accurate: The MaxMind GeoCityLite CSV dataset.
You will need to add a few indexes...
At this point we present the user with an AJAX-ified [top 10] list of Locations matching the highlighted name, sorted in a sensible manner.
the user may modify the search term to refine the list.
Once the user selects the Location from the list, the smw property is set.