I took a look at DBD::mysql's Makefile.PL, and found that it takes its LIBS argument from whatever libs option you provide it with, or from the output of 'mysql_config --libs' if you don't pass it that option. It uses 'mysql_config --cflags' to help find "mysql.h" as well, so it appears that it couldn't find mysql_config.
So, you might try running 'mysql_config --libs' and 'mysql_config --cflags' yourself, and passing the options it shows you to Makefile.PL. On my system the result is something like this:
perl Makefile.PL \ --testdb=test \ --testuser=XXXX \ --testpassword=XXXX \ --cflags='-I/usr/local/mysql/include -O3 -fno-omit-frame-pointer' \ --libs='-L/usr/local/mysql/lib -lmysqlclient -lz -lm'
If your MySQL is in an odd location - and "/usr/local/mysql-standard-4.0.12-apple-darwin6.4-powerpc" certainly qualifies as "odd" - then passing the proper arguments to Makefile.PL is the key to the kingdom.
sherm--