not2easy - 6:16 am on Feb 6, 2013 (gmt 0)

It all depends on how your host has set up their php. One host I work with only needs one line:
AddHandler application/x-httpd-php5 .html .htm
Another host requires this combination:
RemoveHandler .html .htm
AddType application/x-httpd-php .php .html

One host I dropped a long time ago would not work with anything. It wasn't godaddy, but godaddy is one of those kinds of hosts. Lucy24 is right, look and see if your host offers a knowledge base, if not, ask them for their suggestions.
PS it won't work on Windows servers either.