open_basedir and safe_mode_exec_dir

Hi I prefer the php.ini option open_basedir much more over safe_mode to provide virtual hosting for some clients of mine, but to have a little more security, I additionally need to turn off some function with disable_functions (exec, system, shell_exec and popen come to mind). But it would be very convenient, if I could use sth like safe_mode_exec_dir for non_safe_mode mode to allow nevertheless some command line commands. I know, not the best way to enforce security :) Would this be anyhow possible or do we open safe_mode-hell again with such a possibility? another little thingie: the description to open_basedir in the distributed php.ini is between all the safe_mode config, therfore maybe a lot of people don't know, that one can use this whithout safe_mode enabled. chregu