Country name can be grabbed from GeoIP. While not 100% accurate its generally correct.

• Coordinates are useful for those little farmer villages you never heard of.
  
• Map is useful to visualize but doesn't scale by default (needs zoom; see Google Earth) and costs more data than text.
  
• City name works but requires typing. Javascript can help completion, or lists to choose from. Ie. Country -> (State ->) Province / County -> City -> Neighborhood -> ... [Country can use GeoIP to select default option asking user to confirm]
  
• Location_name to coordinates converter probably exist.

GPS can be used too. Or location API from Maemo or Fennec. But by now it is almost becoming a map application. Maybe embed Ovi Maps. LOL. Actually, not an entirely stupid idea. Google does that too...

An option to add the languages one speaks (and allow preferred language, and allow a simple gradation to specify how well) is useful. This helps us understand and empathize with (new) users' communication skills, or allow for more personal help in native language. These not always correlate to the country one lives in. Case in point: qgil. Default suggestion can be primary language in country however some countries have multiple languages or have dialects not widely recognized adding possibility of insulting culture. Usually is same as country but the world is international/globalized these days...

[EDIT: @ Jack, if user knows their exact coordinates and this is converted to Country/../../.. then that is much faster than typing these out or selecting these on map (assume one has to zoom too). I'd say it is safe to assume most people do not know these coordinates.[/EDIT]