Provide link to Geonames while encouraging people to provide link to Geonames

Probably best practice to give the direct link to http://www.geonames.org/ at exactly the moment and place it's recommended:

Note: You must give credit to GeoNames if you are not using the commercial services, for example by including a link to their site on your pages.

Link either "Geonames" or "their site" or put the URL in parenthesis after one of them.

Agaric would also roll a patch for a credit block for GeoNames if people think that ought to be provided, and want to provide the wording ;-)