This post describes how to install MaxMind Geo::IP perl module on Debian Etch.
You need the GeoIP C library (that includes also the free GeoLite Country database). This is fortunately available in the Debian repositories.
apt-get install libgeoip1 libgeoip-dev
To install the GeoIP perl module, we need to download the perl module locally from MaxMind or from CPAN. Uncompress the file and compile.
perl Makefile.PL make make test make install