Country borders

Hi!

I would like to set up a reverse geocoding service which returns the countrycode for a given lat/long-point. Therefore I would need to know the border lines of the European countries (to form a polygon). As I’m new to OSM, I don’t know if there is a possibility to get these borders and if so, how this can be done.
I would really appreciate any help.

Thanks in advance,
Daniel

You might have luck with http://wiki.openstreetmap.org/wiki/Xapi depending on how they’re tagged.