Get the FreeBSD apache-fp port located at:

http://www.westbend.net/~hetzels/apache-fp/

Then configure php using:

./configure --with-apache=/usr/local/Web

It spits this out:

# make
gcc -O2   -I. -I.   -I/usr/local/Web/src -g -Wall   -c language-parser.tab.c
In file included from /usr/local/Web/src/httpd.h:59,
                 from parser.h:167,
                 from language-parser.y:51:
/usr/local/Web/src/conf.h:407: warning: `HAVE_SNPRINTF' redefined
config.h:259: warning: this is the location of the previous definition
In file included from language-parser.y:51:
parser.h:191: parse error
*** Error code 1