CentOS - Feb 2008 - limit number of per-vhost or per-user cgi processes?

Hi List,

Is there a way to limit the number of cgi processes Apache's suExec  
will fork for a given vhost or given user?  (either solution is fine)

suExec doesn't honor the /etc/security/limits.conf nproc value.  
mod_throttle seems to be dead; and I can't figure out if selinux might  
be able to manage this (although would rather not flip selinux from  
permissive to enabled).

What are others doing?

Thanks!

-Jeff