This was useful … Thanks to your tips, my installation was successful on the first go!
I did a plain vanilla installation of MySQL on Snow Leopard, using the 64-bit DMG archive from the MySQL site: mysql-5.1.45-osx10.6-x86_64.dmg.
I used the version of php that came installed with Snow Leopard, but fixed the TimeZone issue per the instructions above.
In setting up WordPress, I followed the step-by-step instructions on the WordPress site, using ‘127.0.0.1:3306’ for DB_HOST in the wp_config.php file (again per the recommendation above).