Ubuntu :: Detailed Logging Of A Specific User?

we are in a place where we have to give an account (with sudo access...) to a user we don't completely trust (I am reminded of this comic). What we need to set up is some way of logging pretty much everything that this user does, especially what he does as root (via sudo or sudo -s). Now, I know that anything we do can easily be undone by another user with root access, but we feel that if he does disable logging we can use this as a really good excuse to revoke his access. So, does anyone know what logging stuff I'd have to set up to completely monitor one user (it is ok if we are monitoring everyone, but we'd prefer to watch one user if possible)?