logging all users command ? via history ?

[Gerik]

hi all,
i am in the need of tracking all my users activities.
i've implemented accounting (acct) but i found that the logs from
accounting is
not enough, it just shows what command was executed but not together
with
their options.
for example, if i executed "vi /etc/hosts", lastcomm wil just show "vi"
and we don't
know what file was opened.
we have "sudo" in place and sudo's log is perfect but the problem is,
sudo
will only logs commands we've told in sudo config files.
So, my question is how do we log users command in bash shell.
i've gone thgrough the manual and found the "HISTFILE" variable.
My question is, how do we set the value of HISTFILE so that we can
put the history to somewhere which is unmodifiable/unwritable by users ?

Or, is there other workaround to this ?

any help is greatly appreciated.

thanks,
--fg