i dislike dtlogin

howto:  disable/enable dtlogin

sol8 & 9

Disable CDE:
# /usr/dt/bin/dtconfig -d

Enable CDE:
# /usr/dt/bin/dtconfig -e

What dtconfig -d & dtconfig -e are actually doing is modifying 
/etc/rc.config.d/desktop (which is in turn called by the CDE rc.script
/sbin/init.d/dtlogin.rc).

sol10

Disable SMF service:
# svcadm disable cde-login

Enable SMF service:
# svcadm enable cde-login