Hello, I did an (unavoidably simple) perl script to migrate album descriptions stored in flat text file (SPGM gallery) to zp, maybe someone will find it useful:
http://www.owczarek.com.pl/blog/2008/01/03/perl-script-to-migrate-from-spgm-to-zenphoto/Pity that only after having written the script I found out that integration with wordpress is not exactly easy (I mean embedding ZP in WP theme like spgm is now, not pulling a single image or gallery).
Btw. I don't follow zp development so closely, but was it ever considered to base on some framework, like Zend? Maybe it could save some time and make the architecture clearer.