gnome-terminal supports the --utmp/--noutmp and --wtmp/--nowtmp
command-line switches, but it's not possible to make utmp/wtmp logging
either on or off by default.  (Given the current code it's on by default).
It's easy to change with a quick source hack, but it'd be nice to be able
to change the default in the config files.

[ It does actually support do_utmp/do_wtmp in config files, but only for
  saved sessions.  And in fact this appears not to work anyway - if I start
  gnome-terminal --noutmp, save the session, log out, and log back in
  again, the restored terminal *does* still register itself in utmp.  ]