This is a technical and specific request for references, software, or expressions of interest in cracking this small problem.

I am about to convert several megabytes of Census data on state and county boundaries to a usable form.  I may actually use some reformatted data files from NationalAtlas.com, depending on what looks like less work.  But I would prefer to use any rational file format if you are aware of one or have created any from the usual public domain sources.  I consider a rational file format to be one that is in ASCII (nominally) delimited or XML, has at least one identifier tag for state or county that is followed by polygon vertex coordinates in decimal (lattitude,longitude) format.  Something that can be digested by a simple computer program.

If you are interested in the solution to this little problem, or the files resulting, I would be happy to send along my findings and boundary files.