You could also think about using geolocation to pre-populate the first box. They have a free database and API that would work for this application: http://www.maxmind.com/app/support
While you're at it, why not expand the site so it contains more information about countries, e.g. include internet country codes. Include currencies for the from and to countries and currency conversions.
In regards to the second idea, I'm trying to keep the site as simple as possible, and adding anything else will only hurt (imho).