do not use the www subdomain for web services, this is not supported and will be taken down.
The ws.geonames.org subdomain is currently having problem. For the time being you can use the ws5.geonames.org domain.
I'd like to follow wonga's second question: Could someone please provide the Code (preferrebly PHP) for generating XML data like the webservice does?
With the obviously high current load on the GeoNames servers I'd like to set up a local mirror. However, the application I use (and which I can't chance) relies on querying a HTTP server/service.