One big gotcha is that PHP is disabled in user home directories by default, so if you are testing from ~/public_html it doesn't work.Check /etc/apache2/mods-enabled/php5.conf
# Running PHP scripts in user directories is disabled by default# # To re-enable PHP in user directories comment the following lines# (from <IfModule ...> to </IfModule>.) Do NOT set it to On as it# prevents .htaccess files from disabling it.#<IfModule mod_userdir.c># <Directory /home/*/public_html># php_admin_flag engine Off# </Directory>#</IfModule>Other than that installing in Ubuntu is real easy, as all the stuff you used to have to put in httpd.conf is done automatically.