MAMP1.9のphp.iniに追記
[xdebug] zend_extension="/Applications/MAMP/bin/php5.3/lib/php/extensions/no-debug-non-zts-20090626/xdebug.so" xdebug.remote_autostart=off xdebug.remote_enable=on xdebug.remote_handler=dbgp xdebug.remote_mode=req xdebug.remote_host=localhost xdebug.remote_port=9000