Hi Russ.

http://www.geonames.org/about.html Looks free to me…

But:

http://wiki.openstreetmap.org/wiki/Geonames

Now, for manual cross-referencing, I can see no problem with using geonames as a data resource. Realistically, how can there be?

Re. DB import and matching to OSM, anyone interested in doing this would need more details on the conditions of use Geonames established with the original name sources (this could possibly make it OK for some locations/countries - but not others) and with Geonames itself re. permission of use. A ‘creative commons attribution license’ is mentioned, but I haven’t looked into the details of this. There’s possible more info on the site - or there’s an email address for Qs.

The OSM wiki mention of geonames seems to dismiss its use with opinion after little investigation. Hardly authoritative, imo.