I continually forget how to do this (because I usually set it up once and never again), so I'm making a quick note of how to show the shortened hostname, username and current directory at the prompt under ksh (the default shell for OpenBSD). In the standard .profile file, enter:
HOST=`hostname`
export PS1='${USER}@${HOST%%.*} ${PWD##*/} $ '
There are ways to add color, etc. to this, but I like the plain, vanilla look it produces. Finally, I won't be likely to run commands on a machine where I shouldn't be.