Something

> diff -u workingenv_orig.py workingenv.py
--- workingenv_orig.py  2006-12-01 10:15:58.000000000 -0500
+++ workingenv.py       2006-12-01 10:17:41.000000000 -0500
@@ -1073,6 +1073,8 @@
 fi
 PATH="$WORKING_ENV/bin:$PATH"
 export PATH
+export PS1_ORIG=${PS1}
+export PS1=${PS1}"@W "
 if [ -n "$_WE_OLD_PYTHONPATH" ] ; then
     if [ "$_WE_OLD_PYTHONPATH" = "__none__" ] ; then
         PYTHONPATH=""
@@ -1109,6 +1111,7 @@
         export PYTHONPATH
         unset _WE_OLD_PYTHONPATH
     fi
+    export PS1=${PS1_ORIG}
     # Self destruct!
     %(unix_unset_env)s
     unset deactivate