Finally found a fix to an svn+ssh issue I was having on Mac OSX.  Great replacement for ssh_askpass on macos:

#! /bin/sh

# An SSH_ASKPASS command for MacOS X

# Author: Joseph Mocker, Sun Microsystems

TITLE=${MACOS_ASKPASS_TITLE:-"SSH"}

DIALOG="display dialog \"$@\" default answer \"\" with title \"$TITLE\""

DIALOG="$DIALOG with icon caution with hidden answer"

result=`osascript -e 'tell application "Finder"' -e "activate"  -e "$DIALOG" -e 'end tell'`

if [ "$result" = "" ]; then

    exit 1

else

    echo "$result" | sed -e 's/^text returned://' -e 's/, button returned:.*$//'

    exit 0

fi

Source/Kaynak : http://blogs.sun.com/jc/entry/svn_ssh_on_macos_x