Off topic : world database

Hi,

I have a slightly off SQL topic question which I don't think is too 
inappropriate,
if it is please let me know and I'll not push my luck again of my 
*favorite email list*.

I'd like to build a Postgresql database of Countries,States and Cities 
of the world.
I would like to use 'earthdistance' module so distance queries are possible.
I plan to expose this data as an SOAP webservice via xmethods.com for 
others to
access as well.

I've been searching for a source for this data without joy so far and 
would like to
ask if someone on this list could point me to or help with a source for 
this info.
Ideally I'd like Country,States,and Cities with Longitude and Latitude 
coordinates.

Thank you kindly,
Again if this is too off topic let me know and I'll keep all my 
questions strictly to SQL.
Regards
Rudi.