I believe I have support for PostgreSQL in the CVS version of Amazon Associate Tools...but I don't have PostgreSQL set up anywhere, so I'm hoping someone will help shake it out (Arto?).
http://drupal.org/files/projects/amazontools-cvs.tar.gz
In particular, the 4.6 version has mixed-case field names (comes from using keystroke macros on Amazon's documentation to build the SQL file). That's been changed to all lower-case, but that means people who upgrade to the CVS version will need to run the commands in upgrade.sql to adjust the field names to lower case. It will then run fine on MySQL (that's been pretty thoroughly tested).
Couple of other small changes...creating related book links for stories, blogs and such still created an amazon-node in the background, but creating an amazon (book review) item does not. And if you delete all related nodes (book reviews, AND stories with related book links) the Amazon record goes away so that it no longer will appear in the random book block. I could do these things without interfering with the way I use the modulemyself, so I did.
Finally, the bulk import page respects the new CVS handling of callback return values and so will not work in 4.6.x.
