Is there a way to retrieve all cities in the world from OpenStreetMap?

I ended up using osmosis with the following call.

./osmosis --read-pbf planet-latest.osm.pbf --tf accept-nodes place=city,town,village --tf reject-relations --tf reject-ways --lp --write-pgsql database=postgis_test user=*** password=***

This seems to contain all cities that I was looking for. Cannot still say much on the data itself. After a couple of test it seems to contain a good amount of places even small villages.

In order to do that I had to however download the full OSM data of about 31 GB.

I haven't used the service, but gisgraphy.com - lists 4.3 million cities available via extract from OSM.