I can never remember how to do this since it varies with the
shell and its always hard to find by
RTFMing.
so
without further ado..
ksh
export PS1='$PWD>'
bash
PS1='\w>'
zsh
export PS1='%~>'
tcsh
set prompt='%~>'
csh
alias cd 'chdir \!* && set prompt="`pwd`>"'
sh
cd() { chdir $* ; PS1="`pwd` >"; }