I must point out that you increase your risk of an exploit if you modify the root PATH, particularly if you insert in front of the path rather than extending it. For instance, if you put the current-dir (".") in the front of the PATH, then any ordinary user can destroy the system by putting a "rm -fr /" inside a file called "/tmp/ls". If root ever cd's to /tmp and types "ls"...bang.

For security purposes, you should never put a directory in the root PATH that ordinary users have write-access to. Additionally, the root user should not rely on the PATH but rather use full pathnames (I realize this additional step is annoying, so adjust your paranoia level accordingly).