I was able to get around the problem of not being able to run fork and exec from Apache php.
I got around this by calling the system 'at' command on Linux. "at run something now". and you have to set atrun -s in a crontab file (to run every minute) to insure that things get kicked off quickly even if there is a heavy load on the machine.
If you're the only one running batch jobs on a linux box, this works.